AB & Anor, R (on the application of) v Secretary of State for the Home Department

In an application to register a child as a British citizen under the British Nationality Act 1981, compliance with the section 55 welfare duty is substantive rather than formal. A decision-maker need not interview the child, make further enquiries, begin with best interests, or expressly address every item of evidence where the available information presents no reason for further investigation and the decision shows that the child’s welfare was materially considered.

The decision-maker may apply the normal section 3(1) expectations, including residence and immigration status, and then assess whether the child’s best interests and any compelling circumstances require an exceptional outcome. A refusal is lawful if, on the information before the decision-maker, it falls within the range of reasonable responses.

The claimants, children living with their parents in Kenya, applied for registration as British citizens under section 3(1) of the British Nationality Act 1981. The Secretary of State initially refused the applications under Schedule 2, paragraph 4, on the basis that the children had not been resident in the United Kingdom for three years. On reconsideration, the Secretary of State considered section 3(1) but refused registration, relying on the children’s future intentions, their parents’ circumstances, residence and immigration status, and the absence of compelling circumstances.

The claimants alleged breach of the section 55 duty, failure to consider relevant matters, irrationality, inadequate reasoning and breaches of Convention rights. The court considered whether the decision was unlawful in substance, having regard to the information available in March 2025 and the guidance governing children’s welfare and section 3(1) registration.

1. Claim refused. The court reviewed the impugned decision on the basis of the information available to the decision-maker in March 2025. Later evidence about travel disruption, schooling and AC’s medical and educational needs could not establish that the decision was unlawful.
2. The section 55 duty under the Borders, Citizenship and Immigration Act 2009 is a duty of substance, not form. The decision letters referred to the duty, treated the children’s best interests as a primary consideration and explained why registration was refused. It was not fatal that the letters did not expressly cite the guidance or state the children’s best interests in those terms. Although section 55(1) refers to children in the United Kingdom, the defendant took no point on the children’s residence abroad.
3. Applying CAO v Secretary of State for the Home Department [2024] UKSC 32, the duty did not require further enquiries or an interview. The applications were made for the children, through lawyers instructed by their parents, and focused on the children’s circumstances. There were no red flags suggesting that the information supplied was incomplete, misstated or inconsistent with the children’s interests.
4. The decision-maker was entitled to consider the normal section 3(1) expectations before asking whether the children’s best interests or compelling circumstances justified an exceptional outcome. That approach was consistent with Zoumbas v Secretary of State for the Home Department [2013] UKSC 74 and R (OBN) v Secretary of State for the Home Department [2024] EWHC 1833 (Admin). The relevant aspect of MK (Sierra Leone) v Secretary of State for the Home Department [2015] UKUT 223 (IAC), insofar as it placed excessive weight on form, was legally erroneous.
5. The scholarship was a relevant matter, but its absence from the express reasoning did not show that it had been ignored. The decision-maker was entitled to give substantial weight to residence, immigration status and the absence of an evidenced intention to settle in the United Kingdom. The refusal was not Wednesbury unreasonable on the information available.
6. The human-rights arguments were not considered because they had not been properly pleaded and their late development would have been unfair to the defendant. The claim was refused, although the children remained free to make a further application under section 3(1).