National Insurance top-up calculator
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Compare the contribution cost quoted by HMRC with the extra weekly State Pension confirmed by DWP. This calculator estimates the time needed to recover your contribution after income tax and the benefit over a period you choose. Missing National Insurance years do not automatically increase your pension, so the starting figures are an illustration rather than a personal entitlement forecast.
Enter the total cost quoted by HMRC and the weekly pension increase confirmed by DWP. The starting values are an illustration for one year, not a personal forecast. Filling a gap does not always increase your pension, especially under pre-April-2016 rules.
- One-off cost
- £956.80
- Extra pension per year, before tax
- £358.28
- Years to recover the cost, after tax
- 3.3 yrs
| Total quoted cost | £956.80 |
|---|---|
| Annual increase before taxYour confirmed weekly increase × 52. | £358.28 |
| Annual increase after income tax | £286.62 |
| Extra pension over 20 years, after tax | £5,732.48 |
| Illustrative gain after the contribution cost | £4,775.68 |
The calculation holds the weekly pension and tax rate constant. It excludes future pension increases, lost savings interest, inflation, benefit reductions and any delay before your extra pension starts. Break-even runs from when you receive the extra pension.
The 2026/27 Class 3 rate is £18.40 a week (£956.80 for 52 weeks), but recent gaps may use their original rate and partial years may cost less. Check the official contribution rates and your State Pension forecast. Ask the Future Pension Centre or Pension Service to confirm the benefit before paying. Source rates checked 12 September 2026.
Official rates & thresholds used
United Kingdom · tax year 2026/27 · last verified . These figures match the parameters embedded in this calculator.
| Parameter | Value | Notes |
|---|---|---|
| Class 3 NI voluntary rate (2026/27) | £18.40 / week | Used only for the illustrative starting cost. Enter your actual HMRC quote; partial years and recent historical gaps can use different rates. |
| Full new State Pension (2026/27) | £241.30 / week | £12,547.60 over 52 weeks at the full rate. Your entitlement depends on your National Insurance record and any pre-April-2016 transitional calculation; check your personal forecast. |
| Total contribution cost used | User input | The total quote from HMRC for all the years being considered. The default £956.80 is an illustration for 52 weeks at £18.40. |
| Weekly pension increase used | User input | Use the total increase confirmed by DWP. The default £6.89 is illustrative; missing years are not automatically multiplied by 1/35 of the full pension. |
Primary sources: HMRC; gov.uk — The new State Pension; DWP. Always confirm live figures on gov.uk before acting.
How it works
- Enter the total HMRC quote for the years you are considering and the total weekly pension increase DWP has confirmed. The 2026/27 Class 3 rate is £18.40 a week (£956.80 for 52 weeks), but partial years and recent historical gaps can cost a different amount.
- The confirmed weekly increase is multiplied by 52 and reduced by the income-tax rate you enter. Dividing the contribution cost by that after-tax annual increase gives the break-even period from when the extra pension starts. A zero increase has no payback.
- For example, a £1,000 quote and a confirmed £5 weekly increase produce £260 more pension a year before tax, or £208 after 20% income tax. The contribution is recovered after about 4.8 years; over 10 years the illustrative gain after the contribution cost is £1,080.
- The calculation holds the pension increase and tax rate constant. It excludes future uprating, inflation, interest you could have earned on your savings, benefit reductions and any delay before payment starts.
Common questions
- Does every missing NI year increase my State Pension?
- No. A year may add nothing if your entitlement is already sufficient, future contributions will fill the shortfall, or transitional rules affect the calculation. Ask the Future Pension Centre, or the Pension Service if you have reached State Pension age, to confirm the increase before paying. This calculator needs that confirmed amount.
- Can I use the calculation for several years of contributions?
- Yes. Enter the total cost quoted for those years and the total weekly pension increase DWP confirms they would produce. Do not multiply a single year's increase without checking that all the years improve your entitlement.
- Class 2 or Class 3?
- Eligibility depends on your circumstances. Some people can pay Class 2; others pay Class 3. Use the actual HMRC quote in this calculator, including any partial-year or historical rate, rather than assuming everyone pays the illustrative Class 3 amount.