Introduction

As of March 2025, nearly 82,000 children lived in state care in England (Department for Education 2025) and a recent nationally representative survey of children in care reported that 94% of them have a sibling. In complex family circumstances, siblings can be children’s main significant relationship (Bank and Kahn 1982; Shlonsky et al. 2005; Silverstein and Smith 2009). As the Children’s Commissioner recently stated: ‘They are often the most loving and important [people] in children’s lives, and [can] be a source of strength, stability and support’ (The Children’s Commissioner 2023, p. 8). Separation from siblings can have lifelong repercussions (The Children’s Commissioner 2023), causing additional trauma, identity confusion and a sense of loss (Kosonen 2001; Wojciak 2017; Wojciak et al. 2023). In contrast, being placed together can create a sense of belonging and emotional connection (Hindle 2000; Leathers 2005; Tarren-Sweeney and Hazell 2005; Hegar and Rosenthal 2011). Research has shown that joint placement can increase placement stability and the likelihood of reunification (Leathers 2005; Tarren-Sweeney and Hazell 2005; Webster et al. 2005; Albert and King 2008; Waid et al. 2016). More recently, it was found that living with at least one sibling can be protective of mental health (Wijedasa et al. 2025).

Recent work with children and young people highlights preferences for terms such as ‘brothers and sisters’ or ‘people who are related to me’ when discussing siblings in care (TACT Fostering & Adoption 2019). However, formal documentation more commonly uses the term ‘sibling’ as a more inclusive term (The Children’s Commissioner 2023), which is used in this paper. The term ‘placement’ is also used in line with policy language and administrative data systems, while recognising that children and young people may prefer terms such as ‘home’ or ‘where you live’ (TACT Fostering & Adoption 2019).

Sibling separation in care

Under the Children Act (1989) in England, local authorities are required to place siblings together in care whenever reasonably practicable and consistent with the child’s welfare. They must also safeguard, promote the child’s overall well-being, and take into account their wishes and feelings. Despite this legal duty, sibling separation remains common. A recent study in England showed that 37% of siblings were separated from at least one sibling when they first entered care (The Children’s Commissioner 2023), and a nationally representative survey of children in care in 2025 found that only 65% of children in care with siblings were living with at least one sibling (Wijedasa et al. 2025).

The reasons for these sibling separations in England are not yet well understood. Only a handful of studies have examined the justifications behind sibling separation in England. Wedge and Mantle (1991), using data from case records of 160 children in 71 sibling groups to study sibling referrals and placements, found reasons included individual needs, wishes of the child and limited placement availability. Disrupted joint placements were attributed to the demand on parental care, financial constraints of the carers or difficulties in siblings’ behaviour and relationships. Dance and Rushton (1999) who interviewed children’s social and placement workers, identified differing needs and placement constraints, and the timing of entry into care as factors. Sharpe’s (2014) interviews with social workers about sibling placement decision-making primarily showed decisions were shaped by practical constraints, such as limited joint placements and time pressures. This was confirmed by the author’s findings (Schmits 2026) that, against the preferred practice of most interviewed social work professionals, siblings were often said to be separated due to practical reasons. Hollows and Nelson (2006) argued, based on five case studies involving large sibling groups, that while early, pragmatic decisions in child placement cases are sometimes necessary, they must be revisited to avoid becoming long-term strategies that overlook children’s rights. More recently, the Children’s Commissioner (CC), examining helpline case studies and interviews with care-experienced young people, also found that siblings were often separated due to a shortage of sufficient placements or different permanence plans for children. The report also argued that children’s needs and views were not sufficiently considered by local authorities (The Children’s Commissioner 2023).

At large, the sibling placement decision involves many different considerations. Recent work (Schmits 2026, under review) highlighted the complexity of this and argued that it involves an interplay between factors around the child and their sibling group (eg, ages, size of group, needs, wishes), the local authority (eg, priority, lack of resources) and external factors (eg, court timelines and view of the public). Importantly, it also highlighted the centrality of the social worker in the decision-making process (see also Sharpe 2014).

Understanding sibling separation: evidence from case files

Interview data does not necessarily evidence the reasoning for separation in individual cases. This is where case files can provide a useful perspective by revealing why separation occurred in specific cases (Wedge and Mantle 1991).

In children’s social care, each child has an individual record within the local authority case management system, where social workers document assessments, decisions and plans about the child’s care journey. Statutory guidance requires practitioners to record their actions, decisions, outcomes and recommendations to support decision-making, accountability, continuity and reflection (Department for Education 2018; Ofsted 2019; O’Keefe and Maclean 2023). Importantly, case recordings are also a key source of information for children themselves, who have a legal right to access their records under the Data Protection Act 2018 (Shepherd and Hoyle 2022). They help care-experienced young people understand their journey, relationships and experiences (Ofsted 2019; Gorin et al. 2024). Apart from the more general statutory guidance on recording, there is currently no specific obligation in national legislation that requires local authorities to explicitly justify and record the decisions associated with sibling placement in children’s case files. Additionally, the government does not request any data from local authorities on sibling placements, and sibling and family identifiers are notably absent from the national data (Department for Education 2023).

So far, only a few studies have used case files to examine sibling separation in care, and overall, the use of case files in research to identify the reasons for sibling separation remains sparse. Staff and Fein (1992) used case file data in the United States in combination with staff interviews for their study on sibling placements, but they did not distinguish what information came from which source, which limits the ability to identify what findings were based on case file data alone. Thorpe and Swart (1992) focused on risk factors that could be extracted from Canadian case files and correlated with sibling separation, thereby using the case files to examine predictors of separation rather than identify recorded reasons for separation. In the English context, over 35 years ago (soon after the introduction of the Children Act 1989), Wedge and Mantle (1991) examined justifications of sibling separation in referrals of sibling groups in England. This study found that for those siblings whose referral included a separation recommendation, 87% included the justification. Although this percentage seems high, it relates to the justification for the recommendation at the point of referral rather than recorded reasons for separation after the decision had been made.

A recent study from the Netherlands (n = 480) more directly examined the recorded reasons for separation using case files. It found that the reasons for separation were not systematically recorded in the case files, and nearly half of the files did not contain any reasoning (Stolwijk et al. 2021). For those files containing information, although not always explicitly stated, practical considerations were noted in 50% of the cases, while the other half reported contraindications as the reason for separation (eg, sibling conflict, behavioural problems or needs for specialist care).

This limited evidence suggests that while some form of justification for sibling separation might be present in case files, systematic recording is limited. Furthermore, at present, there seems to be no available research regarding the extent to which sibling placement decisions are currently documented within local case file management systems in England.

Rationale

By exploring children’s case files from a local authority in England, this study seeks to fill a gap, and address the question: How are reasons for sibling separation documented in children’s social care case files, and what specific reasons are recorded?

Individual children’s social care case files are used to examine recorded reasons for sibling separation. This study examines how these reasons are documented, exploring both the content and format of sibling placement records. It also considers the potential of case file analysis as a method for systematically gathering evidence and identifies ways recording could be improved to support practice, policy and research.

Methods

Ethics

Ethical approval for this study was obtained from the ethics governance boards of the participating local authorities and the University of Bristol. The research followed the UK GDPR data requirements and the Data Protection Act 2018. All data were pseudonymised, and case file extraction data were held within the University of Bristol’s Secure Research Data Storage Facility. Pseudonyms were also used in the results section.

Case file analysis

Social work case files provide comprehensive and valuable data for examining children in care (Hayes and Devaney 2004), although critics question the quality of the case file data, potential inaccuracies and the biased interpretation of events (Teater et al. 2017). A pilot study was conducted to improve validity and reliability by exploring the available data, and piloting data extraction from the case files of 11 children and discussing initial results with social work professionals. The pilot study showed that the reasons for sibling separation were recorded in disparate locations across files, which directed conversations with the operations manager to talk through the key documents that were most likely to contain the information. The pilot study also highlighted the considerable amount of time it required to find and extract the key information from case files, which led to adjustments in the volume of cases to be analysed in the main study.

Data collection and sample

Read-only access was given by one local authority (LA) in England to the case files of all children who entered care for the first time in their local authority between 2015 and 2017, who had been in care for at least 30 days and who had at least one sibling who was already in care or entered care at the same time. This resulted in a sample of 89 cohort children who were part of 38 families. Conversations with social work professionals in this local authority indicated that information on sibling placement decisions and justifications was not located in a single section of the case file, but rather distributed across multiple sections and documents (see Supplementary Material A). When it comes to the definition of siblings used in this study, the sibling relationships as reported in the CMS system were used. However, it is acknowledged that these might not always reflect the child’s definition. In their paper on defining siblings in social work practice, Schmits and Dermott (2026) found that professionals recognised the diversity of sibling definitions going beyond biological ties. However, due to conceptual and logistical challenges in practice, biological and legal definitions often operated as the default in decision-making and recordings.

Consent to access children’s case file data was given by the Director of Children’s Services as the corporate parent of the children. The Director was unable to give consent for children who were placed in care voluntarily (Section 20 agreement under the Children Act 1989) or those who left care for adoption, as this local authority did not have parental responsibility. Therefore, these children, as well as children who only had siblings who were adopted or placed under Section 20, were excluded from the sample. When children had multiple siblings, some of whom were in voluntary care or adopted, those children stayed in the sample; the siblings were noted, but their personal case files were not reviewed.

Analysis

This study used a cross-case thematic analysis of children’s social work case files, combining elements of thematic analysis (Braun and Clarke 2021) and cross-case synthesis (Yin 2017).

Case files of 89 children within 38 families were examined. Because the aim of this study was to examine the reasons for separation, only those sibling groups that were reported to be separated were used in the analysis. Of the 19 sibling groups separated, three sibling groups were separated twice (for example, children were first separated from some of their siblings and later from others as well) and one sibling group was separated three times.

This paper looks at siblings as defined by social work professionals in the case management system (CMS). The CMS includes a relationship section that shows each child’s close relationships, including siblings: sister, brother, half-sister, half-brother, stepsister, stepbrother, foster sister, and foster brother. Furthermore, it is assumed that siblings described in the case file documentation reflect those recorded in the relationship section. This paper recognises that these CMS definitions may not fully reflect the child-led and relationship-based reality of who siblings are for children in care; however, for the purposes of this analysis, these are the definitions available. A previous paper by Schmits and Dermott (2026) provides a more detailed and critical discussion of the challenges of defining siblinghood for children in care.

First, a sibling-focused case description was created, outlining why the children came into care, whether their initial placement was with or without siblings, the reason(s) for separation, and how this pattern of placement together or apart changed over their time in care. It included quotes from relevant documents that were used in the results section. This approach allowed for consistent data extraction across cases, ensured the preservation of the integrity of the individual cases and supported the within-case analysis (Yin 2017).

Secondly, a descriptive framework was developed to help organise the data and identify similarities, differences and themes between the cases. This descriptive framework, often used in cross-case synthesis, gave structure to the analysis and assisted in rigorous analysis (Yin 2017). The rows in the framework represented families, and the columns captured labels of the distinct reasons for sibling separation within the families (see Table 1 for an excerpt of the descriptive framework). When multiple reasons were recorded, these reasons should not be seen as hierarchical.

Subsequently, these labels were analysed and grouped into broader categories inductively (Braun and Clarke 2021) and the categories were added in the columns of the descriptive table (Table 1). Finally, the analysis moved beyond the categorisation to the development of overarching themes. To develop a comprehensive overview of the variety of reasons that were recorded within and across cases, the reason(s) for separation was recorded for each individual separation event. A total of 24 separation events were included in the descriptive framework, indicating that some of the 19 sibling groups experienced multiple separation events.

Both the case descriptions and the descriptive framework were used to support cross-case thematic comparison. The aim of the paper was to explore both how the reasons for separation were recorded in case files and what specific reasons were documented. Therefore, the analysis focused on identifying and interpreting the explicitly stated or implied reasons for separation and in addition, organising these into categories. Components and quotes from case files were used to show how the recorded information was interpreted and to evidence the development and validity of categories.

Results

The practice of recording sibling separation

When it comes to the practice of recording, this section will explore where the information about reasons for sibling separation could be located and how they were presented. First and foremost, it is important to reflect on the fact that relevant information was scattered across 13 different locations within the case file. This highlights the absence of a single, clear place where the underlying reasons for sibling separation were recorded and points to a significant dispersion of information, which makes it difficult to form a cohesive understanding of the decision-making process.

Secondly, the actual recording of sibling separation reasons across the case files was inconsistent. When it came to the recording practices of social work professionals for the 24 separation events, the reasons for three sibling group separation events were not reported at all and for two, they were poorly reported. In some of these cases, the case files showed that the children had either not always lived together (some having temporarily lived with kin through an informal arrangement) or had entered care at different times. In these cases, the documentation failed to clearly convey these circumstances, which highlights the inherent complexity of sibling placements and the challenges of capturing and documenting them. In two of the cases, nothing was reported: the children were placed in emergency placements, and at this point, they were separated. Although we might be able to assume that they were separated because of the difficulty of finding a joint emergency placement, this was not clearly recorded.

For the other 19 separation events, the underlying reasons for separation were often not directly stated. Therefore, the researcher had to infer them from the available information in the case file by analysing reported details concerning sibling placement, circumstances, and separations documented within the case files. Reported details included the views of parents, children and professionals, although these views were not systematically and consistently reported across cases.

Furthermore, statements about siblings and sibling separation were often included within the broader context of the child’s placement decisions but rarely appeared in a dedicated section about the sibling placement decision. More generally, when multiple reasons were documented, it was often unclear from the case files which considerations may have had a greater impact on the decision and what the decision-making process had looked like.

In some cases, a sibling assessment, which is aimed at providing a comprehensive understanding of the quality of the relationship of the siblings and the needs of individual children within the group, was provided. Although a detailed analysis of the use of the sibling assessments is beyond the scope of this paper, it was noted that for nearly half of the separation events (10 out of 24), no sibling assessment or comparable documentation was found, justifying the sibling separation. Furthermore, for some cases, the assessment was only completed at a later stage (not early in the decision-making process), which raises questions about whether it might have served to retrospectively justify a decision that had effectively already been made.

Even though the reasons for separation were eventually identified from the case files for most sibling separation events, this identification and extraction process was challenging. In many cases, it required more than two hours per child to review all relevant documents and find the reasons for separation. This may be reflective of the nature of case file recording and its cumulative character, as well as the organisational context in which records are produced, including staff turnover (Schmits 2026, under review).

Recorded reasons for sibling separation in care

As became clear in the previous sections, there was often no single, clear, overriding reason or justification for separation recorded. Instead, the decision to separate seemed to be driven by a set of implicit or explicit considerations. This reflects the complexity of sibling separation. Across cases, a number of sometimes competing interests and priorities could be identified. However, two themes emerged that closely align with the guidance on sibling placement provided by the Children Act (1989). The first theme, ‘Not in the best interests of the child(ren)’, reflects separation events for which recordings revealed that it was deemed harmful to the child(ren)’s welfare to place siblings together. The second theme, ‘Practical considerations for separation’, reflects situations in which siblings were not placed together due to practical considerations or constraints. These themes provide a structured lens through which this section will examine the reasons for sibling separation in case files.

Not in the best interests of the child(ren): relationships, wishes and needs

Case documentation discussed the behavioural difficulties of (some of) the children and how this could affect other individuals within the group, as well as the relationship between the siblings. For example, in the DeLuca Family, three boys went into care on the same day due to reasons of abuse and neglect and were placed together in a placement. The youngest (only 11 months old) was returned to their parents’ care after only a few weeks; the parents blamed the older boys (aged 9 and 10) for what happened and refused to continue to care for them. The older boys stayed in care, together, in the same placement. However, the professionals were worried about the behaviour of the boys; the child looked after (CLA) review that took place a few weeks after placement reported:

‘V’s behaviour indicates a little boy in extreme stress, he and his brother R will only undertake basic tasks unless with each other, so for example go to the toilet, sleep together etc. […] We are worried about the interaction between the boys which is either overprotective or aggressive. […] There is a lot to understand why V is displaying such behaviour, and he will require a high level of support to reduce his obvious anxieties and high level of fear displayed every day. We believe a lot of this distress follows his younger brother’s return home in the past three days’.

The CLA review highlighted the strong bond between the two boys but also noted a contrasting aspect: the overly protective and aggressive behaviour between them. This may have stemmed from the difficulties they experienced not always having been in the same placement, as suggested in the subsequent CLA review conducted a month later. This behaviour was reported to have influenced the final separation decision. However, supervision records from before the CLA also indicated that the children had to move placements because the carers were ‘unable to manage their behaviour’. In addition, there were mentions of the foster carers’ concerns about how this behaviour affected the other foster child in their home. The foster carers expressed a very clear view that the boys should move to a different placement and that they should not live together. Even though documentation from around the time of the decision suggested that the boys’ behaviour was the main driver of the separation, other sources exposed the foster carers’ inability to manage them, along with concerns about the impact on their other foster child, which appeared to have contributed to the separation.

Other case files highlighted issues around the sibling relationship. This included aggression, older siblings negatively influencing younger siblings, risk of abuse and scapegoating. The case files also clearly showed the changing nature of sibling relationships over time. For example, in the case of the Bloom family, where four siblings were placed in care because one had been abused by their older brother who was not in care. The four siblings were initially placed in two separate pairs but were soon reunited to live together with one of their foster carers, a development that was welcomed by professionals, foster carers, and the children themselves. Early records explicitly discuss the relationship between the three siblings (two girls and a boy, between the ages of 6 and 13) and their abused sister (C, 15 years old):

‘Whilst the three younger siblings are upset that they are not living at home, their relationship with C has remained the same. There is no overt or apparent animosity toward C, and they don’t blame or resent her for their current situation of being in foster care’.

However, a few months after moving into the same place, tensions appeared between C and her siblings. The three siblings expressed that they wanted to go home, and they blamed C for being in foster care. Despite the social worker trying to repair the relationship and considering many options to stabilise the relationship, C requested to move away from her siblings, which then happened. It is unclear from the reports what set off the scapegoating behaviour of the three siblings, or even whether this is how they felt all along, and it was not recognised by the professionals. Regardless, a sibling relationship and joint placement that seemed successful initially broke down after only six months. These breakdowns were not limited to cases involving scapegoating; in other instances, according to the case records, one sibling appeared to abruptly decide they no longer wished to live with their siblings. The reasons behind this sudden change were not always evident from the recordings, but a similar pattern was observed in multiple cases.

Not only did the case files highlight how the changing relationships of siblings over time could influence decisions, but more generally, how situations, behaviours, and wishes could change over time.

The Taylor family

For the Taylor family, a sibling group of four, the initial plan was to place them in sets of two: the girls A and S (10- and 9-year-old) and the boys E and L (8- and 6-year-old) were to be placed together. A and S were placed together initially but separated half a year later due to the behavioural issues of S. A and S also expressed the view that they did not want to live together. However, due to a placement breakdown of A, they ended up together in a placement again. Subsequently, the social work professionals decided the girls should stay together (the sibling assessment was positive about joint placement). However, due to behavioural issues of A and the need for one-to-one attention of S, the girls were finally separated in the long term. For E and L, the plan was to keep them together, but in two subsequent placements, the foster carers could not deal with their behaviour, which led to the long-term separation of the boys.

This case description, in addition to findings of other cases, stresses not only the multitude of reasons for separation but also the changes to children’s behaviour, wishes, needs and available resources over time and the variability during those times in what the involved parties felt was the best decision for the child(ren) with regard to sibling placements. In addition, it highlights that pursuing a shared placement is not without risks, given the instability that the children in this case experienced.

In all cases where the child’s wishes were (one of the) reason(s) for sibling separation, the child wished to be separated from all their siblings, not just some. The wishes and voices of the children were not always clearly articulated in case files. However, in those cases where they were recorded, the final decisions did most often align with the children’s expressed wishes.

In some case files, social work professionals reported different needs as a reason for separating siblings. For example, for an older child (15 years old) who had taken on a caring role for both her mother and her brother (9 years old) for an extended time, the court plan dictated: ‘We would place M separately from her siblings. This would give M the opportunity to be a teenager and develop and grow without being a young carer for her brother’. Other needs, those more complex in nature, such as health needs, developmental delays and communicational, behavioural or social needs, were often reported to be too difficult to manage, mostly when siblings within a group had different needs, and caused the social work professional or the foster carer to decline the joint placement. This again shows how often not just the different needs of the children cause the social work professional to separate the children, but rather the fact that those different and combined needs were difficult to manage by foster carers. The needs only seemed to be directly influencing separation when these related to the permanency plans; for example, the plan for the younger siblings was adoption and older siblings’ long-term foster care.

Practical considerations for separation: constraints of resources and carer capacity

As became clear in the previous section, often it was not just considerations around the welfare of the children, but also the practical constraints that caused the sibling separation.

A lack of resources was often noted in case files as a reason for separating siblings: ‘The current sibling placement has broken down due to highly complex sibling dynamics and the local authority has not been able to identify a suitably robust sibling placement as an alternative’.

Notably, when the lack of placements for sibling groups was one of the considerations influencing the sibling placement decision, it was often referenced later in the documentation and with less emphasis. This happened, for example, in the case files of the Price Family children. The siblings in the Price Family, two boys (B and C) and one girl (A), between the ages of 8 and 11, were reported to have expressed views about living together; A wanted to be placed with B, and C did not want to be placed with A. However, the decision quickly moved towards: ‘the plan is to place them separately’. It was reported that this was based on individual needs; the local authority did not think joint sibling placement was in their best interest due to the complex needs and sibling rivalry. A later report described how the two brothers started blaming the abused sister for being in care. Throughout the reports, there were many mentions of the need for a sibling assessment. However, it was never completed. Altogether, the decision to separate was presented as due to their needs and relationship; however, in a CLA review, nine months after the children entered care and were separated, it suddenly appeared it was also a resource issue: ‘Following early CSC assessments, A and her two older brothers were removed from the family and placed in separate foster placements. This was because CSC did not have sufficiency to place them together’. This raises the question of how much these considerations influenced the overall narrative surrounding the decision to separate siblings.

Resource issues often went beyond simply lacking sufficient placements for (complex) sibling groups. More significantly, it often related to the suitability, capability, and willingness of foster carers as well as the assumptions made by social workers in this regard. For one group of siblings (four), the case files showed that even without having started a search for foster carers, it was already decided that caring for these siblings together would be too much for foster carers to manage; the assumptions about the capability of potential foster carers directly influenced the decision: ‘A lot of discussion was around the possible options of how to best split the children. It was agreed that all three or possibly four of the children would be too much for one set of foster carers to manage’.

Multiple cases referred to the inexperience of the foster carers or their perceived inability to manage the multiple siblings, with a variety of needs. One case note indicated: ‘Is this more about the carers’ lack of experience than the children’s behaviour? This will need to be explored further’. In other cases, it was reported that seemingly singular events had caused the foster carers to be unwilling to care for one of the siblings anymore. In one case, it was related to an argument that followed a drug incident in school. Interestingly, the social workers appeared to suggest that the foster carers may have ‘given up’ too quickly, as the incidents described could be seen as a typical part of parenting young people. ‘It is disappointing that this has taken place, there had been lots of discussions recently about supporting the placement and the fostering agency supported the need for the carer to take ownership of challenges’. More generally, the case files suggested that foster carers were often in a position of relative power and could use this to ensure decisions aligned with their preferences. They usually took on cases they felt able to manage and would end placements, perhaps more quickly than social workers would have liked, if it was not working for them. This dynamic may have led to sibling separations in cases where they could potentially have stayed together. The case of the DeLuca family, for example (see previous section), where the foster carers were adamant about moving the boys to new, separate placements, showed the potential strong influence foster carers might have.

Discussion

This paper aimed to answer the question: How are reasons for sibling separation documented in children’s social care case files, and what specific reasons are recorded?

Recorded reasons for sibling separation: insights from case files

By using cross-case synthesis of children’s social care case files, it was found that often siblings were separated because social work professionals did not think it was in their best interest to live together. Specific reasons that were found in the case files were behavioural issues, wishes or needs of the child(ren). These could be purely individual reasons, for example, one child wishes to live without their siblings. But the reasons could also be related to the sibling relationship, for example, scapegoating behaviour towards one sibling. These results align with the other studies that were conducted in England, but used different methods. It shows that the best interests of the children is taken into account when considering their sibling placement options. However, standardised assessments of the siblings’ relationship and needs (eg, a sibling assessment) seemed to be lacking for many sibling groups. It is outside the scope of this paper to go into more depth on why this might have been the case, and more generally, the practice of conducting sibling assessments before deciding on sibling placements. However, it is something that is important to consider for practice, since it could provide the structured and focused narrative that is needed in case files to inform and justify sibling placement decisions (Department for Education 2018; Ofsted 2019; O’Keefe and Maclean 2023; Gorin et al. 2024).

However, reasons why siblings could not be placed together due to practical constraints were also identified in many case files. For example, case files would highlight separation due to placement unavailability, but more importantly, the inability or unwillingness of foster carers to manage siblings. Similar to the author’s other study (Schmits 2026), the case file analysis showed that individual separation events were often caused by more than one reason, and in line with previous research, the practical, resource-related reasons were frequently amongst them (Wedge and Mantle 1991; Dance and Rushton 1999; Hollows and Nelson 2006; The Children’s Commissioner 2023). These findings have important implications for policy and practice. In particular, they suggest that the practicability principle in the Children Act (1989) may sometimes act in conflict with the best interests principle. The findings suggest that the ambiguous direction of the principles of practicability and best interests potentially leave room for justifying separations that could have been prevented (Joint Committee on Human Rights 2008).

Narratives in case files showed changes in circumstances, behaviours, wishes, needs and opinions of involved parties (eg, children, carers, social workers) regarding sibling placements in care. This shows the importance of viewing sibling placement decisions as an ongoing dynamic, rather than a one-point-in-time judgement, with the ‘right’ sibling placement decision evolving over time as circumstances and relationships change. This aligns with UN Committee General Comment No. 14 (2013), which emphasises that the child’s best interests must be understood as a dynamic concept requiring continuous assessment as situations evolve. The dynamic nature of the sibling placement decisions also highlights the importance of regularly reviewing siblings’ living arrangements, with looked-after children’s reviews providing a clear opportunity for this (UN Committee on the Rights of the Child 2013).

This study found very little explicit evidence in case files about factors related to the decision-maker that would influence the decision to separate siblings. Even though social work professionals in practice often engage in extensive reflection processes, the written case files constructed by social work professionals did not reflect on the extent to which interpretations, values and assumptions of social work professionals influence their decision-making around sibling separation. This lack of explicit evidence in the case files may underrepresent the role of social workers’ values and judgments. Research shows that professional judgement is generally not value-neutral, but shaped by normative considerations about what counts as a life worth living (Evans 2017). Given the vagueness of the Children Act’s best interest standard, Thomson (2021) suggests the capability approach as a source of clearer ‘normative language’ (Deneulin 2006) to support decision-making.

Overall, this study indicates the potential of children’s social care case files to offer insights into the reasons why siblings are separated in care. Case files can offer more distinct and case-specific insights compared to administrative data, while still allowing examination of relatively large samples. Especially with regard to sibling placement, it can give more in-depth knowledge about why siblings are separated and how multiple reasons might interrelate on a case-by-case basis. Therefore, it has the potential to uncover detailed patterns of reasons why separation takes place.

How reasons for sibling separation are documented

The study also examined how reasons for sibling separation in care were documented. The evidence on sibling placement decisions for some separation events was absent or unclear, but for the majority of separation events, the considerations behind the decision to separate siblings could be found in the case documentation. However, the lack of structure around recording the separation meant it was difficult to extract these reasons. The range and variety of documents and locations of the recorded reasons increased the chances that relevant information was overlooked. The reported content around the separation reasons also varied in detail: some considerations were briefly noted and hidden in the text, while others were clearly explained and linked to sources like sibling assessments.

The findings of this study show how the accessibility and systematic documentation of information around the decision-making of sibling placement could benefit from improvement. Files often reflected many considerations rather than a few explicit reasons, and the researcher had to read across the file and infer the considerations that led to the decision. This has implications for accountability, transparency and the child’s right to understand the decision-making around the separation. This lack of consistent recording may reflect both limited time for reflective casework and care planning practices that do not fully reflect the importance of sibling relationships and recording guidelines, and systems that do not explicitly ask for sibling placement information.

Improving the recording of sibling placement decision-making would help young people who access their records find out why they were separated from siblings. A longitudinal story that describes what happened to their sibling placements over time, and why those arrangements did or did not change, should be recorded. Improving sibling placement recording could also help research to more systematically answer questions about siblings in care. Knowing why siblings are separated could highlight potential areas for improvement and drive appropriate recruitment, training and support for carers. In other words, if the reasons for separation are difficult to find, local authorities are not able to learn from the past and create the evidence base necessary to improve the future for siblings in their care.

Limitations and directions for future research

This study did have limitations. Obtaining ethical approval for access to case files proved to be a lengthy process. Initial discussions began with four local authorities; two progressed to a subsequent stage, although one of them withdrew at the last minute due to conflicting opinions on the ethics around accessing case files. In terms of research on sibling separation in care, conducting comparable research at multiple local authorities could examine any differences in the reasons for sibling separation and the recording of these between local authorities.

Whereas the initial plan was to review a larger volume of case files and use the extracted reasons for separation for a quantitative analysis, this turned out not to be feasible due to time demands. Finding the reasons for separation was a complex and time-consuming process due to the dispersion of the information.

The rich data from the 19 sibling groups examined in this study provided a comprehensive picture of the issue of sibling separation and, more specifically, what could be learned from case files about this issue. However, it has not offered insights into how social workers, who often serve as the central decision-makers in this process, construct narratives around sibling separation, how they interpret events, and how they make meaning out of them. This would add value to our understanding of the social worker’s role as a decision-maker in sibling placement within care.