State Pension Top-Up Calculator
Work out whether paying voluntary Class 3 National Insurance to fill gap years in your record is worth it. See the cost per year, how much extra State Pension you'd get, your payback period, and the total extra income across your retirement.
The Class 3 rate and full pension used for the calculation.
From your State Pension forecast — you need 35 for the full new State Pension.
How many missing years you could pay voluntary Class 3 NI to fill.
The age you can start claiming your State Pension.
Used to estimate the lifetime value of the extra pension. UK average is ~age 86–88.
£4,615
£923 per year (52 × Class 3 weekly rate)
£1,710
Now 25 of 35 qualifying years
2.7 years
Years of extra pension to recover the cost
£35,916
Across 21 years drawing your pension (gross)
Cumulative cost and the lifetime extra income each filled year buys, to age 88.
| Years filled | Cumulative cost | Lifetime extra income |
|---|---|---|
| 1 | −£923 | +£7,184 |
| 2 | −£1,846 | +£14,368 |
| 3 | −£2,769 | +£21,551 |
| 4 | −£3,692 | +£28,735 |
| 5 | −£4,615 | +£35,919 |
Check eligibility and deadlines first
Contact the Future Pension Centre before paying — they confirm whether topping up will actually increase your pension. Some pre-2016 years may not increase your new State Pension, and there are deadlines for filling older gaps.
How State Pension Top-Ups Work
Class 3 voluntary National Insurance
Your State Pension is based on your National Insurance record, not how much you earned. If you have gaps — years where you didn't work, were abroad, or weren't claiming credits — you can often pay voluntary Class 3 contributions to fill them. Each full year costs 52 times the weekly Class 3 rate (£18.20 a week, or about £946, in 2026-27).
The 35-year rule
To get the full new State Pension you need 35 qualifying years of National Insurance. Each qualifying year is worth 1/35th of the full pension. With fewer than 35 years you get a proportionate amount, and with fewer than 10 years you usually get nothing. Filling a gap year therefore adds about 1/35th of the full pension — roughly £349 a year in 2026-27 — for the rest of your life.
Why the return is so good
Paying about £946 to buy roughly £349 a year of extra pension means you recover the cost in under three years. After that the extra income is effectively free, and it rises each year with the triple lock. Very few other investments offer a guaranteed, inflation-protected return like this.
Deadlines and who benefits
Topping up makes sense if you have gaps and will reach State Pension Age with fewer than 35 qualifying years. It does not help if you already have 35 years, or will reach 35 through future employment or National Insurance credits (for example while claiming Child Benefit or carer's credits). Some pre-2016 years may also not increase your new State Pension. There are also deadlines for filling older gaps, so always confirm with the Future Pension Centre before paying.
Frequently asked questions
How much does it cost to top up?
A full year of voluntary Class 3 National Insurance costs 52 times the weekly Class 3 rate. For 2026-27 the rate is £18.20 a week, so one full year costs about £946. You pay this to fill a gap year in your National Insurance record.
How much extra State Pension do I get?
Each qualifying year adds 1/35th of the full new State Pension. For 2026-27 the full pension is £234.85 a week, so one extra year adds roughly £349 a year for the rest of your life, rising with the triple lock.
What is the payback period?
Dividing the cost of one year (about £946) by the extra annual pension it buys (about £349) gives a payback of under three years. After that, the extra pension is effectively free income for the rest of your retirement — one of the best returns available.
Who should not top up?
If you already have 35 qualifying years, or will reach 35 through future work or National Insurance credits, paying voluntary contributions won't increase your new State Pension. Some pre-2016 years may also not boost it. Always check with the Future Pension Centre first.