Missing 5 years: the maths
If you have 5 qualifying years missing on your NI record, here is what filling them costs and what it earns you back.
5 years at a glance
Total Class 3 cost
5 x £923 per year
£4,615
Weekly SP uplift
£34.45 per week
Annual SP uplift
£1791.40 per year
Payback period after SPA
around 2.6 years
20-year lifetime gain
£35,828.00
Class 3 buy-back calculator
Total cost
£4,615.00
Weekly pension uplift
£34.47
Annual pension uplift
£1,792.51
Payback period
2y 7m
20-year lifetime gain
£35,850.29
When buying 5 years makes sense
- You have at least 5 gap years 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 years 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 5 additional years now lifts their effective count toward the 35-year cap. At a Class 3 cost of £4,615, the uplift is £1791.40 per year. Across a 20-year retirement that is £35,828 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