What Are Class 3 NI Contributions?
Class 3 National Insurance contributions are voluntary payments you can make to HMRC to fill gaps in your National Insurance record. They are specifically designed for people who are not working or not earning enough to pay compulsory NI, but who want to build up their entitlement to the State Pension.
Unlike Class 1 contributions (paid by employees) or Class 2 contributions (paid by the self-employed), Class 3 contributions are entirely optional. You choose when and how much to pay, and each year you fill adds a qualifying year to your record, which in turn increases your State Pension entitlement.
Class 3 Rates: What Does It Cost?
The Class 3 NI contribution rate is set each tax year by HMRC. Here are the rates for recent and current tax years:
| Tax Year | Weekly Rate | Annual Cost | Payment Deadline |
|---|---|---|---|
| 2019/20 | £15.00 | £780.00 | 5 April 2026 |
| 2020/21 | £15.40 | £800.80 | 5 April 2027 |
| 2021/22 | £15.40 | £800.80 | 5 April 2028 |
| 2022/23 | £15.85 | £824.20 | 5 April 2029 |
| 2023/24 | £17.45 | £907.40 | 5 April 2030 |
| 2024/25 | £17.45 | £907.40 | 5 April 2031 |
| 2025/26 | £17.45 | £907.40 | 5 April 2032 |
| 2026/27 | £17.45 | £907.40 | 5 April 2033 |
Payment Deadlines
The standard rule is that you have six years from the end of the tax year to pay voluntary Class 3 contributions. After this deadline, the gap is permanent and cannot be filled.
For example:
- The 2020/21 tax year ended on 5 April 2021 – you have until 5 April 2027 to fill this gap
- The 2021/22 tax year ended on 5 April 2022 – you have until 5 April 2028
- The 2026/27 tax year ends on 5 April 2027 – you have until 5 April 2033
How to Pay Class 3 Contributions
Paying Class 3 contributions involves a few steps. Unlike some HMRC payments, you cannot simply log in and pay online – you need to contact HMRC first.
Step 1: Identify Your Gaps
Check your National Insurance record online at GOV.UK. Your record will show which tax years are complete qualifying years and which have gaps. It will also tell you the reason for any gaps.
Step 2: Confirm the Payment Will Help
Before paying, call the Future Pension Centre on 0800 731 0175. They can confirm whether filling a specific gap year will actually increase your State Pension. This is essential because in some situations – particularly if you were contracted out of the Additional State Pension – additional years may not increase your pension.
Step 3: Contact the NI Contributions Office
Call 0300 200 3500 to arrange payment. They will calculate the exact amount owed for each year you want to fill and provide a payment reference. Note that if you only need a partial year to complete a qualifying year, the cost may be less than the full annual amount.
Step 4: Make the Payment
You can pay using the following methods:
- Direct debit: Set up regular quarterly payments. This is useful if you want to pay for the current tax year as you go
- Bank transfer (Faster Payments or BACS): Use the sort code and account number provided by HMRC, along with your unique payment reference
- Cheque: Send to HM Revenue and Customs, National Insurance Contributions Office, BX9 1AN
Is Paying Class 3 Worth It?
The financial case for paying Class 3 contributions is compelling in most situations. Here is the arithmetic:
- Cost per year: £907.40 (2026/27 rate)
- Additional annual pension per year bought: approximately £342
- Payback period: approximately 2.7 years
If you reach State Pension age at 67 and live to the average life expectancy (around 86 for women, 83 for men), you could receive the additional £342 per year for 16 to 19 years. That is a total return of £5,472 to £6,498 from a single £907 investment.
For a more detailed analysis of whether buying missing years is right for you, see our guide: Can I buy missing NI years?
Class 3 vs Class 2: Which Should You Pay?
If you are eligible for Class 2 contributions, you should always choose Class 2 over Class 3. The cost difference is substantial:
- Class 2: £3.45 per week (£179.40 per year)
- Class 3: £17.45 per week (£907.40 per year)
Both count equally as a qualifying year for State Pension purposes. Class 2 is available to self-employed people with low profits and to certain people working abroad. If you think you might be eligible for Class 2, check with HMRC before paying the higher Class 3 rate.
For a full comparison, see our guide on voluntary National Insurance contributions.
Partial Year Payments
You do not always need to pay the full annual amount to complete a qualifying year. If you worked for part of a tax year and paid some NI contributions, you may only need a small top-up payment to turn that year into a full qualifying year.
For example, if you worked for six months in a tax year and paid NI for those months, you might only need to pay for the remaining 26 weeks at £17.45 per week (£453.70) rather than the full £907.40.
HMRC can calculate the exact shortfall when you call the NI Contributions Office.
Who Cannot Pay Class 3 Contributions?
There are some situations where you cannot pay Class 3 contributions:
- You have already reached State Pension age for the years in question
- The six-year time limit has passed for the gap year
- You already have a full qualifying year for the year in question
- You are under 16
Record Keeping
Keep detailed records of all voluntary NI contributions you make, including:
- The tax year(s) you are paying for
- The amount paid
- The date of payment
- Your HMRC payment reference
- Confirmation from HMRC that the payment has been received and applied
It can take several weeks for HMRC to update your NI record after receiving payment. Check your record online after a few weeks to confirm the gap has been filled.