Mona Chang v The Secretary of State for the Home Department

For paragraph 276A(a)(v) of the Immigration Rules, “18 months” means 548 days. A calendar month cannot lawfully be treated as 30 days merely because administrative guidance adopts that calculation. Where the Rules are ambiguous, guidance may assist an applicant only where it adopts a favourable interpretation. It cannot impose a substantive requirement which determines whether an application succeeds. Such a requirement is an immigration rule requiring the statutory procedure under section 3(2) of the Immigration Act 1971.

The appellant sought indefinite leave to remain on the basis of ten years’ long residence. The First-tier Tribunal accepted the respondent’s approach that 18 months equated to 540 days and dismissed the appeal, including on article 8 grounds.

The appellant appealed to the Upper Tribunal, arguing that the First-tier Tribunal had failed to interpret paragraph 276A(a)(v), had misunderstood the meaning of a calendar month, and had impermissibly relied on guidance. The central issue was the number of days represented by “18 months” for the purpose of calculating total absences from the United Kingdom.

1. Appeal allowed. The First-tier Tribunal had made a material error of law. Its decision was set aside and remade.
2. “Month” is not defined in the Immigration Rules. Under section 5 and Schedule 1 to the Interpretation Act 1978, the ordinary statutory meaning is a calendar month, unless a contrary intention appears. A calendar month is calculated by reference to the calendar, not by multiplying a fixed number of days. The number of days therefore varies according to the months involved.
3. Using calendar months to aggregate separate absences creates uncertainty because the total number of days may vary. In ordinary usage, 18 months means a year and a half. Depending on leap years, that period is 547.5, 548 or 548.5 days. Applying the usual rounding convention, the correct interpretation is 548 days.
4. The respondent’s guidance, which treated 18 months as 540 days, adopted a different and less favourable meaning. It therefore sought to create a substantive requirement affecting entitlement to leave. Applying R (Alvi) v Secretary of State for the Home Department [2012] UKSC 33, that could not lawfully be achieved through guidance.
5. The appellant had spent 543 days outside the United Kingdom and therefore satisfied paragraph 276A(a)(v). She met the long-residence requirements in paragraph 276B. In light of the respondent’s concession, there was no public interest in removal and removal would breach article 8. The appeal was allowed on human rights grounds, with the judgment directing that indefinite leave to remain should be granted.

• First-tier Tribunal: The appeal was dismissed. The tribunal treated 18 months as 540 days and found removal proportionate.
• Upper Tribunal (Immigration and Asylum Chamber): Permission to appeal was granted. The First-tier Tribunal decision was set aside for material error of law, and the appeal was remade and allowed on human rights grounds.