Missing 1 year: the maths
If you have 1 qualifying year missing on your NI record, here is what filling it costs and what it earns you back.
1 year at a glance
Total Class 3 cost
1 x £923 per year
£923
Weekly SP uplift
£6.89 per week
Annual SP uplift
£358.28 per year
Payback period after SPA
around 2.6 years
20-year lifetime gain
£7,165.60
Class 3 buy-back calculator
Total cost
£923.00
Weekly pension uplift
£6.89
Annual pension uplift
£358.50
Payback period
2y 7m
20-year lifetime gain
£7,170.06
When buying 1 year makes sense
- You have at least 1 gap year that fall within the eligible window (typically 6 years back from the current tax year)1
- You have not yet hit the 35-year cap on your forecast
- You expect to live at least 2.6 years past SPA, the rough payback period
- Adding the year actually moves your figure (call the Future Pension Centre before paying)2
Worked example
Person A is 5 years from SPA with 28 qualifying years. Buying 1 additional year now lifts their effective count toward the 35-year cap. At a Class 3 cost of £923, the uplift is £358.28 per year. Across a 20-year retirement that is £7,165.6 in extra income.
Adjacent
By Oliver Wakefield-Smith, Founder, Digital Signet.
Rates current for 2026/27 · Verified Q2 2026 · Next refresh after Autumn Budget 2026