Clarifying the Durable Partner Requirement under the EU Settlement Scheme (EUSS)

Introduction

Mustaj v Secretary of State for the Home Department ([2025] EWCA Civ 663) is a Court of Appeal decision addressing the interpretation of a single, technically complex paragraph—sub-sub-sub-paragraph (b)(ii)(bb)(aaa)—in Annex 1 to Appendix EU of the Immigration Rules. The question was whether that provision could ever be satisfied by an individual who, before the end of the EU–UK transition period, had no lawful basis to remain in the UK. Mr Fatjon Mustaj, an Albanian national who entered the UK illegally in 2017, married a Romanian national with pre-settled status under the EU Settlement Scheme (EUSS) in April 2021 and then applied for limited leave to remain under the EUSS. His application was refused at every stage on the ground that he could not qualify as a “durable partner” on 31 December 2020, the end of the transition period. The Court of Appeal was asked to decide whether the exception in paragraph (aaa) could bring someone without any lawful basis of stay within the definition of “durable partner.”

Summary of the Judgment

The Court of Appeal (Falk LJ giving the lead judgment, with whom Bean and Underhill LJJ agreed) dismissed the appeal. It held that

paragraph (b)(ii)(bb)(aaa) of the durable-partner definition naturally excludes anyone who had no lawful basis of stay in the UK before 31 December 2020;
the exception introduced by the word “unless” applies only to those whose only reason for not being resident “as” a durable partner was that they did not hold a residence card and who otherwise had a lawful basis to remain;
Mr Mustaj, who was in the UK unlawfully until his marriage, fell within the exclusion and therefore was not a “durable partner” under Appendix EU;
the court did not need to decide whether he had in fact formed a durable relationship by the specified date (ground 1); the appeal failed on the construction of paragraph (aaa) (ground 2).

Analysis

Precedents Cited

Celik v Secretary of State for the Home Department [2023] EWCA Civ 921 – sets out the legislative background of the EUSS, its basis in the Withdrawal Agreement and Directive 2004/38/EC, and the scope of appeal rights under the Immigration (Citizens’ Rights Appeals) Regulations 2020.
Hani (EUSS durable partners: para (aaa)) [2024] UKUT 68 – an Upper Tribunal decision interpreting paragraph (aaa) in line with the Secretary of State’s narrow construction; relied on by the UT below.
Mahad v Entry Clearance Officer [2009] UKSC 16 – confirms that the Immigration Rules are to be interpreted “sensibly according to the natural and ordinary meaning” of the words used.
Odelola v Secretary of State for the Home Department [2009] UKHL 25 – emphasizes construction against relevant background and purpose.
Inco Europe Ltd v First Choice Distribution [2000] 1 WLR 586 – authorizes correction of clear drafting errors by adding or omitting words.
Hoque v Secretary of State for the Home Department [2020] EWCA Civ 1357 – an example of the Court of Appeal correcting a mis-placed sentence in the Immigration Rules.
Pokhriyal v Secretary of State for the Home Department [2013] EWCA Civ 1568 – guidance can be used to resolve ambiguities in the applicant’s favour, but not in the Secretary of State’s favour.
Other authorities (e.g. Rexhaj [2024] EWCA Civ 784; Kabir; Alijaj) illustrate the drafting challenges posed by Appendix EU.

Legal Reasoning

The Court applied the following principles in interpreting paragraph (aaa):

Natural and ordinary meaning: The Rules are administrative policy turned into statutory form; the court must discern from the text what the Secretary of State intended (Mahad, Odelola).
Contextual reading: Paragraph (aaa) sits within a multi-layered definition of “durable partner” in Annex 1 to Appendix EU, which itself feeds into the eligibility test in paragraph EU14.
Qualitative requirement: The first half of paragraph (aaa) refers to being “resident … as the durable partner … on a basis which met the definition.” That is a qualitative inquiry into the capacity in which the person was resident.
“Unless” caveat: The second half of paragraph (aaa) starting “unless the reason why …” excludes from the first test only those whose sole reason for not having been so resident was (a) the absence of a relevant EEA-Regulation document and (b) the presence of another lawful basis of stay.
Rejection of the appellant’s construction: Mr Mustaj’s reading would render “unless” meaningless and produce an absurd result—giving better treatment to those unlawfully resident than to those lawfully present on other visas.
No reliance on later revised paragraph: The Court refused to treat the April 2023 revision as shedding light on the original text, since the rules must be construed as they stood at the relevant time (Inco Europe).

Impact

The decision has immediate and wider significance:

It confirms that any person who was in the UK unlawfully before the end of the transition period cannot qualify as a durable partner under paragraph (b)(ii)(bb)(aaa) of Annex 1 to Appendix EU.
It provides authoritative guidance for pending appeals that turn on the construction of paragraph (aaa), avoiding divergent interpretations in the tribunals.
It underscores the practical importance of securing a lawful basis to remain—such as through an EEA-Regulation residence card—before relying on alternative EUSS routes.
It adds urgency to the Law Commission’s longstanding recommendations for simplification and improved drafting of the Immigration Rules, particularly Appendix EU.

Complex Concepts Simplified

EU Settlement Scheme (EUSS): A post-Brexit scheme granting EU/EEA/Swiss nationals (and certain family members) UK residence rights broadly mirroring the Withdrawal Agreement.
Specified date: 11 pm on 31 December 2020—the end of the UK’s transition period following EU exit.
Relevant EEA citizen: An EU/EEA/Swiss national (or British citizen) with status under the EUSS.
Durable partner: A person in a long-term relationship akin to marriage with an EEA citizen, evidenced either by two years’ cohabitation or “other significant evidence,” plus additional documentary and residency tests.
Relevant document: A residence card issued under the EEA Regulations before the specified date or pursuant to an application made before that date.
Paragraph (b)(ii)(bb)(aaa): A sub-sub-sub-paragraph creating an exception for durable partners who lacked an EEA document but had another lawful basis to stay; it does not apply to those with no lawful basis.

Conclusion

The Court of Appeal’s thorough dissection of paragraph (b)(ii)(bb)(aaa) settles a key point of EUSS law: a person who was unlawfully resident before 31 December 2020 cannot be a “durable partner” under that provision. The appeal was therefore dismissed without needing to resolve whether Mr Mustaj had in fact formed a durable relationship by the specified date. Beyond its immediate effect, the judgment highlights the pressing need for the Home Office to simplify and clarify the Immigration Rules—especially Appendix EU—to ensure that lawyers, adjudicators and applicants alike can understand and apply them without months of strained analysis.