United Kingdom — From ILR to British Citizenship (Timeline and Absence Limits)

Summary

Wait after ILR

12 months (none for spouses of British citizens)

Residence period

5 years ending on the application date (3 for spouses)

Absence limit

≤ 450 days in 5 years (≤ 270 in 3)

Final-year limit

≤ 90 days in the last 12 months

Anchor day

In the UK on the day exactly 5 (or 3) years before applying

Basis

British Nationality Act 1981, s. 6 and Sch. 1

Getting Indefinite Leave to Remain is not the end of the road. To become a British citizen by naturalisation under section 6(1) of the British Nationality Act 1981 you must have held ILR or settled status for 12 months before applying, have 5 years of lawful residence ending on your application date, and stay within two absence limits: no more than 450 days outside the UK across those 5 years and no more than 90 days in the final 12 months. You must also have been physically in the UK on the day exactly 5 years before you apply. Spouses and civil partners of British citizens use section 6(2): no 12-month wait, a 3-year period, and a 270-day limit instead of 450.

Who it applies to

This timeline matters most if you are:

• Newly settled — you have just received ILR and want to know the earliest date you can apply for citizenship and what you must avoid in the meantime.
• A frequent traveller whose absences during the visa years were fine for ILR’s 180-day rolling rule but may sit close to the cumulative 450-day citizenship limit.
• Married to or in a civil partnership with a British citizen and eligible for the shorter section 6(2) route.
• Planning a long trip or overseas posting after ILR and wondering how it affects the citizenship clock.

The absence limits themselves are explained in detail in the naturalisation residence requirement rule; this article is about how they fit into the timeline that starts with ILR. For how you reach ILR in the first place, see the ILR guide.

The rule — step by step

Schedule 1 of the British Nationality Act 1981 sets the residence requirements for naturalisation. Read as a timeline, they work like this:

• Step 1 — settle. You obtain ILR or settled status. From this point your immigration permission has no time limit, which is what the Act calls being free of immigration time restrictions.
• Step 2 — hold it for 12 months. Under section 6(1) you must have been free of immigration time restrictions for the 12 months ending on your application date. Section 6(2) waives this for spouses and civil partners of British citizens, who can apply as soon as they hold ILR.
• Step 3 — check the 5-year residence period. The period is the 5 years ending on the day of application (3 years for spouses and civil partners). It includes your visa years before ILR. You must have been physically present in the UK on the first day of that period — the day exactly 5 (or 3) years before you apply.
• Step 4 — check the absence limits. No more than 450 days outside the UK in the 5 years (270 in 3 years for spouses), and no more than 90 days in the final 12 months. Both must be met at the same time.
• Step 5 — the other requirements. Good character, the Life in the UK test and the English language requirement. The last two are usually already satisfied from your ILR application.

Why the sequence exists: ILR shows you have made the UK your home; the extra 12 months shows that you have stayed once you were free to leave. The cumulative 450-day limit looks at the whole 5-year picture, while the 90-day final-year limit checks that you are still living here at the moment you ask to become a citizen.

Counting the days

Choose a provisional application date and test it against each requirement:

1. 1Confirm the date is at least 12 months after your ILR was granted (unless you apply under section 6(2) as the spouse or civil partner of a British citizen).
2. 2Go back exactly 5 years (or 3) from that date. Check your travel records: were you physically in the UK on that day? If not, shift the application date until you were.
3. 3Add up every day you spent outside the UK between that anchor day and the application date — all trips combined. The total must be 450 days or fewer (270 for the 3-year route).
4. 4Separately, add up every day outside the UK in the final 12 months before the application date. That total must be 90 days or fewer.
5. 5If either limit is exceeded, move the application date later so that older trips drop out of the window, or accept that you would be relying on Home Office discretion.

The free naturalisation absence calculator runs both absence checks from your trip dates and lets you try different application dates. Because the 5-year period reaches back into your visa years, the same trip list you used for the ILR absence calculator carries straight over.

Examples

Example 1 — the standard 6-year journey

You arrived on a Skilled Worker visa in June 2020, kept every rolling year under 180 days away, and received ILR in June 2025. You can apply for citizenship from June 2026. Your 5-year window then runs from June 2021 to June 2026: 320 days abroad in total and 40 in the last year, so you meet both limits. You were in the UK in June 2021, so the anchor-day requirement is met too.

Example 2 — ILR-compliant but over the citizenship limit

Across your visa years you travelled heavily for work — never more than 150 days in any rolling 12 months, so ILR was never at risk — but the 5-year total comes to 520 days. That is over 450 and beyond the 480 days the guidance normally considers for discretion. Waiting until the busiest trips age out of the 5-year window is the safer course.

Example 3 — the spouse route

You are married to a British citizen and received ILR in March 2026. Under section 6(2) there is no 12-month wait: you can apply straight away, provided you were in the UK in March 2023, your absences over those 3 years are 270 days or fewer, and you spent no more than 90 days abroad in the last 12 months.

Example 4 — a long absence after ILR

Shortly after ILR you take an 18-month posting abroad. The final-year limit is broken for at least a year after you return, and the 5-year total is likely over 450 too. Stretch that posting past 2 years and ILR itself lapses under the two-year absence rule, which resets both the settlement and the citizenship clocks.

How Bounded helps

A citizenship application asks for every absence in the 5-year period with dates, and that period reaches back into the years you were building towards ILR. Bounded is a country-days tracker that counts each day outside the UK automatically, so the record already exists when the ILR chapter ends and the citizenship one begins:

• One trip list, two applications. The log that produced your ILR absence record is the same log the citizenship form needs — Bounded keeps counting through settlement, so nothing has to be reconstructed.
• Both limits at once. The cumulative 450-day total and the 90-day final-year total are tracked as separate counters against a chosen application date, so you can see which one is binding and how moving the date changes it.
• The anchor day. Because every day is recorded, you can check whether you were in the UK on the day exactly 5 years before your intended application date and pick a date that works.
• After ILR. Long trips after settlement are the most common way to derail this timeline. Bounded shows how an absence affects the 90-day and 450-day counters and how close it comes to the 2-year lapse threshold. The naturalisation absence calculator gives the same checks without an account.

Bounded records where you were; it does not assess good character or predict how the Home Office will exercise discretion. For those, rely on the GOV.UK guidance linked above.

Exceptions & edge cases

• Spouses and civil partners of British citizens (section 6(2)). No 12-month wait after ILR, a 3-year residence period, and a 270-day absence limit. The 90-day final-year limit and the anchor-day requirement still apply.
• Discretion over excess absence. Published guidance describes normally disregarding total absences of up to 480 days over 5 years (300 over 3 years) and up to 100 days in the final year in some circumstances, and considering larger excesses only where there are strong reasons. This is discretion exercised on the facts of each case, not an entitlement.
• Leaving the UK for 2 years after ILR. ILR normally lapses after a continuous absence of more than 2 years. If that happens you are no longer free of immigration time restrictions, the 12-month ILR clock restarts once you regain settlement, and the residence period is affected too — see the 2-year absence lapse rule.
• Good character. A separate requirement assessed at the citizenship stage; the absence limits are only part of the picture.
• Language and Life in the UK. Usually already met at ILR, so most applicants do not need to sit the tests again — but confirm this against current GOV.UK guidance for your circumstances.

Common misconceptions

• "I need 5 years after ILR before citizenship." No — 12 months holding ILR is the wait. The 5-year residence period counts backwards from the application date and includes your visa years.
• "If my absences were fine for ILR they are fine for citizenship." Not necessarily — ILR uses a rolling 180-day-per-year test, while citizenship uses a cumulative 450-day cap plus a 90-day final-year cap. Steady travel that never troubled the ILR rule can exceed 450 over 5 years.
• "The 480 and 100-day figures are the real limits." They are not. The statutory limits are 450 and 90; the higher figures describe where the Home Office may exercise discretion, which it is not obliged to do.
• "Once I have ILR I can live abroad and come back to naturalise." Long absences break the 90-day and 450-day limits, and more than 2 years away lapses ILR altogether, sending you back to the start of both clocks.

Frequently asked questions

Sources

• GOV.UK — British citizenship
• GOV.UK — Apply for citizenship if you have indefinite leave to remain
• GOV.UK — Naturalisation as a British citizen by discretion: nationality policy guidance
• legislation.gov.uk — British Nationality Act 1981, Schedule 1