Class 3 contributions are voluntary National Insurance payments that turn a gap in your record into a qualifying year for State Pension. For the 2026 to 2027 tax year they cost £18.40 a week, you can normally only fill gaps from the past six tax years, and HMRC’s own guidance warns that paying does not always increase your State Pension, so check your forecast and your entitlement to free credits before you pay anything.

What does a Class 3 contribution actually buy?

Class 3 contributions exist under section 13 of the Social Security Contributions and Benefits Act 1992 (SSCBA). Section 13(1) lets people over 16 pay them if they wish, and section 13(2) says payment is allowed only so that the contributor can acquire the earnings factor needed to satisfy the contribution conditions for benefit. In plain terms, you are buying qualifying years. HMRC says voluntary contributions count towards your State Pension and some benefits, and for most people the State Pension is the reason to pay.

A tax year counts as a qualifying year when your earnings factor reaches the qualifying earnings factor, which section 122 of the SSCBA defines as the lower earnings limit for the year multiplied by 52. HMRC’s National Insurance Manual at NIM25001 explains that where your earnings factor from Class 1, Class 2 and Class 3 is below that figure, you may pay Class 3 for the year in order to reach it. That is why a year that is partly covered by work or credits usually costs less than a full year to fill: the online record tells you the actual cost.

Section 14 sets the limit the other way. You cannot pay Class 3 for a year in which Class 1 contributions paid or treated as paid, or Class 2 contributions actually paid, already reach the qualifying earnings factor.

Who is allowed to pay Class 3?

GOV.UK sets out who can pay, based on status:

  • Employed: you earn less than £129 a week and you are not eligible for National Insurance credits.
  • Self employed: your gross income is £1,000 or less, or it is over £1,000 but profits are below £7,105. You can pay Class 2 or Class 3.
  • Unemployed: you are not claiming benefits and not getting credits.
  • Over State Pension age: you can still pay Class 3 to fill gaps within the time limit.

You cannot pay voluntary contributions if you have no gaps, if you are a married woman or widow paying reduced rate National Insurance, or if the deadline for the gap year has passed.

The rules for time abroad changed on 6 April 2026. For periods abroad from the 2026 to 2027 tax year onwards, voluntary Class 2 is no longer available, and Class 3 for time abroad after 5 April 2026 needs either 10 years in a row living in the UK or 10 years of qualifying contributions. The old test was three years. Applications for time abroad use form CF83, and the wider rules are covered in National Insurance when working abroad.

How far back can you pay, and at which rate?

GOV.UK states that you can only pay voluntary contributions for the past six tax years, with a deadline of 5 April each year. Its own example is that gaps for 2025 to 2026 can be filled until 5 April 2032. Applying the same rule, a gap in 2020 to 2021 has to be paid by 5 April 2027.

The weekly Class 3 rates published by HMRC are:

Tax year Class 3 rate a week
2026 to 2027 £18.40
2025 to 2026 £17.75
2024 to 2025 £17.45
2023 to 2024 £17.45

Which rate you pay depends on timing. Section 13(4) of the SSCBA charges a late Class 3 contribution at the rate for the year it covers, but section 13(6) switches to the higher rate where payment is made after the end of the next tax year but one. GOV.UK puts this simply: if you pay Class 3 for the previous two tax years you pay the original rate, and for any earlier year you pay the current rate. So a 2024 to 2025 gap paid during 2026 to 2027 costs £17.45 a week, while a 2021 to 2022 gap paid now costs £18.40.

How do you check whether paying is worth it?

Do this before paying, in this order:

  1. Check for free credits. GOV.UK advises checking eligibility for National Insurance credits first. A parent registered for Child Benefit for a child under 12, or a carer, may already be entitled to the year at no cost.
  2. Read your record and forecast. The online National Insurance record shows your gaps, whether you would benefit from paying, how much it would cost and whether you can pay online. Our guide to reading your NI record explains what the entries mean.
  3. Ask if unsure. Below State Pension age, contact the Future Pension Centre. At or over State Pension age, contact the Pension Service. If you live abroad and are over, or within six months of, State Pension age, contact the International Pension Centre.

Paying adds nothing if you are already on course for the full rate. GOV.UK explains that each qualifying year after 6 April 2016 increases your State Pension only up to the full rate, which is £241.30 a week for 2026 to 2027. It also warns that voluntary contributions do not always help, for example if you were contracted out, and that contracted out people usually need more than 35 qualifying years to reach the full rate.

What does the arithmetic look like?

Illustration only. Sam is 60 and has an empty year for 2021 to 2022. Sam’s forecast shows a pension below the full rate at State Pension age even after working until then, and the online service confirms that filling the year would increase it. A full year paid now costs 52 weeks at £18.40, which is £956.80, because 2021 to 2022 is more than two years back.

GOV.UK says each extra qualifying year adds about £6.89 a week to a new State Pension that is below the full rate. Over a year that is roughly £358, so Sam recovers the cost in under three years of drawing the pension. The real figure is lower for a taxpayer, because the State Pension is taxable income (see how the State Pension is taxed), and nothing is gained if Sam’s forecast already reaches the full rate.

How do you pay?

  • Online through the State Pension forecast service, if you are below State Pension age and working in the UK. This route is not available if you are self employed or have lived or worked abroad. HMRC says the record updates within 5 working days.
  • Bank transfer or online banking to HMRC NIC Receipts, quoting the 18 digit reference on your payment request. If you do not have one, get it from the forecast service or ask HMRC. A wrong reference can send the money to a different tax bill.
  • Regular payments for the current or future tax years, by monthly Direct Debit or quarterly bills, using form CA5603. Direct Debit cannot be used for past years.

Apart from the online forecast route, HMRC says the record can take up to 8 weeks to update. If 5 April falls on a weekend or bank holiday, make sure the money reaches HMRC on the last working day before it.

Should a self employed person pay Class 2 instead?

Usually, if eligible. Self employed people with profits below £7,105, or gross income of £1,000 or less, can choose voluntary Class 2 at £3.65 a week for 2026 to 2027, a fraction of the Class 3 rate. GOV.UK also lists people in specific jobs who do not have Class 2 treated as paid but may pay voluntarily: examiners, moderators and invigilators, landlords eligible to pay Class 2, ministers of religion without a salary or stipend, and people making investments other than as a business and without a fee. Our guide to self employed National Insurance covers how Class 2 is treated when profits are higher.

What mistakes cost people money?

  • Paying for a year that credits would have filled free, such as a Child Benefit year.
  • Paying for years that will not raise the pension because future working years will reach the full rate anyway.
  • Missing the 5 April deadline for the oldest year, after which the gap normally cannot be filled.
  • Leaving a recent gap until it falls outside the two year window and is charged at the higher current rate.
  • Expecting the current year to show on the record: the online record only runs to the start of the current tax year, 6 April 2026.

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Sources

Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 8 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.