Your 2020/21 NI year disappears in April — here's what that actually costs you

There is a deadline in the UK pension system that no letter, no app notification and no employer will ever mention to you. Since the transitional window that allowed buying years back to 2006 closed in April 2025, voluntary National Insurance has reverted to its standing rule: you can fill gaps in your record for the last six tax years only. The consequence is a rolling annual expiry — every 5 April, the oldest open year shuts for ever.

Right now, the years from 2020/21 onwards are still buyable. On 6 April 2027, 2020/21 is gone. If you left the UK in 2020 or earlier and have paid nothing since, you are standing at the high-water mark of what can still be repaired — and the tide only goes out.

What one year is actually worth

The full new State Pension needs 35 qualifying years; each year is therefore worth roughly 1/35th of the pension — about £342 a year, for life, index-linked, from state pension age. Against that:

Class 2 is available to expats who were employed or self-employed in the UK immediately before leaving and who work abroad — which describes most people reading this. There is no investment product on any shelf, anywhere, with that risk-adjusted return. The money is trivial; the eligibility window is what expires.

The one-sitting decision

1. Pull your NI record and State Pension forecast from your personal tax account (ten minutes, assuming your Government Gateway still works from abroad — a separate saga we've written up here).
2. Ignore the headline forecast — it assumes you keep contributing. Find the "based on your record so far" number and count your qualifying years against 35 (minimum 10 to get anything).
3. Check for contracted-out history. A COPE note on the forecast means your starting amount was adjusted — some people need more than 35 years, and occasionally a bought year adds nothing. This check is the difference between informed buying and hopeful buying.
4. Decide which back years to take. Not all gaps are equal: a year with partial credits can sometimes be completed for a fraction of the full price — the best value on the board.
5. File the CF83 for ongoing Class 2 and pay the chosen back years. Processing from abroad runs to months, which is precisely why the decision shouldn't wait for the March before an expiry.

Who should let years expire without regret

Anyone certain of reaching 35 clean years anyway — a 30-year-old planning decades of future UK employment is buying insurance they'll never claim. Anyone whose contracted-out arithmetic caps the benefit. And anyone who can't plausibly reach the 10-year minimum at all. Roughly one in five people we review shouldn't buy — which is exactly why the £149 review exists: we've priced telling you no at the same rate as telling you yes.

One more April is one more year gone. This is the rare tax decision where doing it this month rather than next spring has a hard, dated payoff.

A worked case, because the abstractions hide the money

Sarah left for Singapore in August 2021 after nine UK working years, and has paid nothing since. Her open gaps today: 2021/22 through 2025/26 — five years, all Class 2 eligible, roughly £900 the lot. Bought, they take her banked years from nine to fourteen; combined with ongoing Class 2 until state pension age she reaches the full 35 comfortably. The five back-years alone add about £1,710 a year to her eventual pension — £900 in, £1,710 out every year of retirement. Left another two years, 2021/22 and 2022/23 expire and that recoverable pension drops by nearly £700 a year, permanently. The gap between acting this year and 'sometime' is a compounding, dated, four-figure difference — which is rare in personal finance and worth treating with respect.