Buying back missing National Insurance years, and when it isn’t worth it

Few things in retirement planning look as straightforward as paying a few hundred pounds now for extra State Pension for the rest of your life. Sometimes it really is that good a deal. Sometimes it buys nothing at all. The difference lies in the detail of an individual National Insurance record, and getting it wrong in the second direction means paying HMRC for a year that changes nothing.

This article sets out what voluntary contributions cost for 2026/27, what a year can add, the deadlines, and the situations in which GOV.UK itself says a payment will not increase the pension.

What a gap is, and why it appears

A gap is a tax year that does not count as a qualifying year for the State Pension. GOV.UK lists the usual reasons: being employed on low earnings, being unemployed without claiming benefits, receiving National Insurance credits for only part of a year, being self-employed with small profits and not paying, or living or working abroad. Gaps are common, and they do not always matter, because a person may have more qualifying years than they need.

What it costs in 2026/27

Most people filling gaps pay Class 3 voluntary contributions. Some self-employed people, and some who have lived abroad, can pay the cheaper Class 2 instead.

Weekly rates from GOV.UK. Annual figures are the weekly rate × 52, for illustration. For Class 3 gaps in the previous two tax years the original rate for that year applies; for earlier years the current rate applies.

The six-year window

GOV.UK is clear on the deadline: voluntary contributions can usually be paid only for the past six years, and the deadline is 5 April each year. Its own example is that gaps in the 2025/26 tax year can be filled until 5 April 2032. Once a year falls outside the window, it normally cannot be bought back. Special extended deadlines that applied to older years in the past have now closed.

What a year can add

Under the new State Pension, each qualifying year that counts adds one thirty-fifth of the full rate. At the 2026/27 full rate of £241.30, that is about £6.89 a week, or roughly £358 a year, and it is uprated each April with the rest of the pension.

A voluntary contribution only has value if that particular year would change the pension. The forecast says whether it would.

When it isn’t worth it

GOV.UK warns that voluntary contributions do not always increase the State Pension, giving contracting out as an example. In practice, the cases to watch for are these:

• The full rate will be reached anyway. Someone still working who will build up enough qualifying years before State Pension age gains nothing from filling an older gap.
• The starting amount is already at or above the full rate. People whose 2016 starting amount exceeded the full rate receive a protected payment; extra years do not add to it. Our explainer on why so many people receive less than the full new State Pension covers how the starting amount was set.
• Credits would fill the gap for free. GOV.UK advises checking eligibility for National Insurance credits before paying. Grandparents and other relatives who looked after a child under 12 while the parent worked, for example, may be able to have credits transferred for those years.
• Pension Credit would be reduced. For someone whose income would qualify them for Pension Credit, extra State Pension can reduce that benefit, leaving little or no overall gain.
• The year is a reduced-rate year. Married women and widows who were paying the reduced rate cannot pay voluntary contributions for that period.

How to check before paying

1. Check the National Insurance record on GOV.UK. It shows any gaps, what filling them would cost, whether doing so would increase the pension, and whether payment can be made online.
2. If below State Pension age, check the State Pension forecast. GOV.UK also suggests contacting the Future Pension Centre, which can say whether a payment would help.
3. If State Pension age has already been reached, contact the Pension Service, which GOV.UK names as the place to find out whether voluntary contributions would increase an existing pension.
4. If living or working abroad and close to State Pension age, contact the International Pension Centre first. The rules for people abroad changed from 6 April 2026.

Who this matters for, and what to check

• People within a few years of State Pension age whose forecast is below the full rate.
• People who spent years abroad, or who were self-employed on low profits, and have gaps inside the six-year window.
• People who have already reached State Pension age and have a recent gap: the Pension Service can say whether it would add anything. If deferring as well, see what putting off your State Pension adds.
• Anyone weighing the cost against other uses of savings: the general rules on how the full rate is uprated are in how the triple lock decides each April’s increase.

The takeaway

Buying back a missing year costs £956.80 at the 2026/27 Class 3 rate and, when it counts, adds about £6.89 a week for life, a return that takes under three years to recover. When it does not count, it adds nothing. The official record and forecast show which is which, free of charge, and they should be checked before any money changes hands.