British citizenship
Absences and British citizenship: the 450-day rule
Enter your total days abroad and those in the last 12 months. The tool places them in the Home Office bands; the page explains how to count them.
How the Home Office treats my absences
Whole period
Over by 30 days or less: discretion normally used
| Limit for this route | 450 days |
| Band with conditions | 480 to 900 days |
| Last 12 months | 91 to 100: discretion used |
Bands of the Home Office nationality guidance (version 16.0). A caseworker decides; nothing here is a decision.
For naturalisation the Home Office checks two windows of absence. Over the whole qualifying period you may spend up to 450 days outside the UK on the 5-year route, or 270 days on the 3-year route for spouses and civil partners of British citizens. Separately, the 12 months ending with your application date may contain no more than 90 days abroad on either route. Only whole days count: the day you leave and the day you come back are both treated as days in the UK, so a trip out on 22 September and back on 23 September counts as zero. Weekends away therefore weigh little and long stays weigh a lot. You list every absence on the form from your own records, and the Home Office compares the list with its entry and exit records and your passports. Totals a little above the limits can still be accepted under the guidance on discretion.
Where does my qualifying period start?
You must be in the UK on
2 December 2021
| Period | 5 years |
| Absences allowed in it | 450 days |
| Last 12 months start | 2 December 2025 |
The day after the application date minus the period, as in the guidance’s example (1 September 2022 → 2 September 2017).
Questions, dates and fees by Radif Partners · Editorial policy · Method
How to count a trip
The rule is printed in the nationality guidance: count whole days outside the UK only, never the dates of departure and arrival. In practice, the number of days abroad for one trip is the number of nights away minus one.
| Trip | Left | Returned | Days counted |
|---|---|---|---|
| Day trip to Paris | 6 March | 6 March | 0 |
| Weekend in Amsterdam | Friday 14 March | Sunday 16 March | 1 |
| Family visit | 3 April | 17 April | 13 |
| Summer abroad | 20 July | 3 September | 44 |
| Total for the year | 58 |
That year stays well within 90 days even with a six-week summer away. Repeat the pattern every year of a 5-year period and the total is 290, still under 450; on the spouse route, 3 such years make 174, under 270. Add one long trip of a few months and both windows can tip over at once.
Two windows, one application date
Both limits are measured backwards from the day the Home Office receives your application. The whole-period window runs from the first day of the qualifying period (the day after the application date minus 5 or 3 years). The final-year window is the 12 months ending with the application date. A long trip that sits 13 months before you apply weighs only in the first window; push the application back by two months and it can drop out of the final year entirely, though it still counts in the period. Planning around that is legitimate, and the date calculator does it trip by trip.
Proving where you were
You declare absences on the form; the Home Office checks them. Guide AN lists what it relies on:
- Your passports covering the period, even where they were not stamped on entry.
- Home Office records of entry to and exit from the UK, which you do not need to request yourself.
- If passports are missing, letters from employers with start and end dates, payslips, P60s, letters from colleges or from other government departments.
- Doctors' letters only as a last resort, and only if the doctor saw you regularly over the period.
Documents you uploaded with earlier immigration applications need not be sent again: the Home Office already holds them. If your trips do not fit in the space on the form, Guide AN says to add them as a separate attachment. The nationality guidance tells caseworkers to give the benefit of the doubt where claimed absences are within normal limits and nothing suggests the list is wrong.
Mistakes that turn up again and again
- Counting departure and return days. It overstates the total, sometimes by a hundred days over a long period with frequent travel, and can make people wait a year for nothing.
- Forgetting the final year. A period total of 300 days looks safe on the 6(1) route, but if 120 of them fell in the last 12 months the application is above 90.
- Leaving trips off the list. The Home Office compares your list with its own records; an omission raises questions of accuracy that a full list would never have raised.
- Ignoring the first day. Being abroad on the first day of the period is a separate problem from the totals; the tool below gives that date.
- Assuming time abroad while waiting for ILR does not matter. Every day of the qualifying period counts, whatever status you held at the time.
If your totals are above the limits, read the page on excess absences before deciding to wait. Very long absences raise a separate risk to settlement itself, explained on the time abroad page.