Your State Pension forecast — and plugging the gaps

Arriving in the UK part-way through your career inevitably creates gaps in your National Insurance record. The good news: you can often plug those gaps with voluntary contributions, and the payback period is surprisingly short. Before paying a penny, though, check your State Pension forecast on gov.uk — it is free and will tell you exactly what you are missing and whether topping up is worth your money.

Check Your Forecast First

Start here. You must sign in to gov.uk/check-state-pension with your Government Gateway login. If you do not have a Government Gateway account, you can create one in about ten minutes; you will need your National Insurance number, date of birth, and address.

The forecast will show you how much State Pension you could receive weekly, what age you can claim it, and how many qualifying years you have accumulated so far. It will also flag any gaps in your National Insurance record and tell you whether filling them would actually increase your pension entitlement. This last point is crucial: there is no point paying to fill gaps if you already have enough qualifying years.

You need a minimum of 10 qualifying years on your National Insurance record to get any State Pension at all. The full new State Pension (for those reaching State Pension age on or after 6 April 2016) requires 35 qualifying years. If you have fewer years than that, you will receive a proportionally reduced amount.

Voluntary Class 3 Contributions: The Basics

Voluntary Class 3 National Insurance contributions let you buy back missing years and boost your State Pension. You can normally fill gaps in the last six tax years. For example, in 2026/27 you could fill gaps going back to 2020/21. Each year you fill costs £956.80 (the rate for 2026/27), and each qualifying year you add is worth approximately £359 per year to your State Pension for life.

The maths is straightforward: if one year of contributions costs around £957 and adds roughly £359 a year to your pension, you break even in roughly three years of retirement — and then you are gaining pure income. Most people who have gaps find it an excellent investment, but always check your forecast to be sure.

Deadline warning: the extended window is closing

Normally you can only fill gaps going back six years. However, the government had extended a special deadline allowing people to fill gaps all the way back to 2006/07. That extended deadline closed on 5 April 2025. From now on, the standard six-year rule applies. If you have older gaps, they cannot be recovered. Check your forecast immediately if you arrived in the UK several years ago.

Important change for expats: April 2026 restrictions

From 6 April 2026, new restrictions apply to expats and those living abroad who want to pay Class 3 contributions. If you are submitting a new application to pay Class 3 for periods worked abroad from the 2026/27 tax year onwards, you must now have either lived in the UK continuously for at least 10 years, or have built at least 10 qualifying years on your National Insurance record (not counting voluntary contributions paid for work abroad). If you already have an existing arrangement to pay Class 3, these new rules do not affect you immediately, but it is worth understanding them if your circumstances change.

How to Pay Voluntary Contributions

Unlike many HMRC payments, you cannot simply go online and pay. You must contact HMRC first to confirm which years you can fill and get an invoice.

1. Call the Future Pension Centre on 0800 731 0175 (0191 218 3600 from abroad)
2. Or write to the National Insurance Contributions Office (HMRC will provide the address)
3. Tell HMRC which gaps you want to fill
4. HMRC will confirm the cost and send you payment instructions
5. You can then pay by direct debit, bank transfer, or cheque

Payment deadlines apply: you have until 5 April each year to pay for a gap that arose six years prior. For instance, gaps in 2024/25 can be filled until 5 April 2031. Once the deadline passes, you cannot recover that year.

Years Worked Abroad: Check for Social Security Agreements

One of the most valuable things an expat can check is whether time worked abroad might count toward the UK State Pension via social security agreements. The UK has bilateral agreements with many countries that allow you to combine National Insurance contributions from both countries. This can make the difference between falling short of the 10-year minimum and qualifying for a pension.

If you have lived or worked in an EU or EEA country (including the European Economic Area), Switzerland, or certain countries with formal social security agreements with the UK (such as Canada, New Zealand, and the United States), time you spent paying into that country's social security system may be credited toward your UK State Pension qualifying years when you claim.

Important caveat: the amount of pension you actually receive is based only on the qualifying years from your UK National Insurance record. But if counting your overseas contributions gets you to the 10-year minimum, you will qualify for a pension even if you have fewer than 10 UK years. This is a critical distinction that catches many expats unaware.

For example: you have 7 UK qualifying years and worked in Spain for 8 years, paying into the Spanish system. When you claim, the UK will recognise your Spanish contributions to help you meet the 10-year threshold. However, your actual pension will be calculated on your 7 UK years only, not the combined total.

How to check if your overseas work counts

Contact the International Pension Centre (part of the DWP) before you pay any voluntary contributions. They can tell you whether time you spent working or paying social security in specific countries will count toward your qualifying years. This could save you hundreds of pounds in unnecessary voluntary contributions.

Have ready: details of which countries you lived or worked in, the dates you were there, and (if possible) evidence of your contributions in those countries — employment contracts, payslips, or letters from the overseas tax authority.

State Pension Uprating: A Warning for Expats

If you plan to retire abroad, there is one more critical thing to understand. The UK State Pension increases each year for those living in the UK, the EEA, Gibraltar, Switzerland, and a handful of other countries with formal social security agreements. However, if you retire to countries like Australia, Canada, New Zealand, or much of Asia, your pension will be frozen at the rate you first claimed it, even as the cost of living rises.

This is not a reason to skip voluntary contributions — the return is still excellent — but it is essential context for your long-term financial planning. Make sure you understand whether your intended retirement destination has an uprating agreement with the UK.

The Sum of It

Arriving mid-career in the UK leaves you with National Insurance gaps, but you are not stuck with them. Plug the gaps strategically: start with a free forecast on gov.uk, check whether any overseas work counts via social security agreements, and then decide which years are worth buying back. Voluntary Class 3 contributions typically pay for themselves within a few years and provide lifetime retirement income. The key is to check before you pay, respect the deadlines, and not assume every gap needs filling. A little planning now will mean thousands of pounds extra in your pocket in retirement.