British citizenship absence calculator
Add your trips outside the UK and a planned application date to check both naturalisation limits, and find the first date they both fit if they don’t yet.
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The two limits
To naturalise as a British citizen you need to have lived in the UK for a qualifying period before you apply, with limits on time away. Both are counted back from the day the Home Office receives your application:
- Standard route: no more than 450 days outside the UK in the 5 years before you apply.
- Married to, or the civil partner of, a British citizen: no more than 270 days in the 3 years before you apply.
- Both routes: no more than 90 days outside the UK in the last 12 months.
As with settlement, only whole days count: the day you leave and the day you come back are UK days.
A worked example
You plan to apply on September 1, 2027 on the standard route. Your trips over the years add up to 318 whole days away in the 5 years before that, well under 450. But two recent trips, November 20, 2026 to February 10, 2027 and July 2027, put 110 days in the last 12 months: 20 over.
If you don’t travel again, those 20 days drop out of the 12 months one by one. Applying on December 10, 2027 instead, the last 12 months hold exactly 90. The calculator finds that date for you.
Timing your application
Because both limits count back from the application date, waiting a little can move a long trip out of the window. Try a few dates in the calculator. The Home Office can use discretion for absences a little over the limits, especially when the rest of your life is clearly in the UK, but it is safer to apply when you are inside them.
Questions people ask
Which day does the 5-year period end on?
The day the Home Office receives your application. The 5 years (or 3 on the spouse route) and the last 12 months are both counted back from there.
Do I also need to have held ILR for 12 months?
On the standard route, usually yes: you need settled status for 12 months before applying. If you are married to or the civil partner of a British citizen, you can apply as soon as you have it.
Are the day I leave and the day I return absences?
No. Only whole days outside the UK count, as for settlement.
I am over the limit. Can I still apply?
The Home Office can use discretion, and it is more likely when the excess is small and your home, family and work are in the UK. The safer option is often to wait until enough days have dropped out of the window.