National Insurance Gaps: What HMRC’s Letters to the Self-Employed Mean

If you’re self-employed and a letter has landed from HMRC about gaps in your National Insurance record, take a breath. It isn’t a bill. It doesn’t automatically mean anything is wrong. HMRC is writing to up to 800,000 self-employed people about possible National Insurance gaps that could reduce their State Pension. It’s worth understanding what HMRC actually wants before you do anything.

Why National Insurance gaps happen

The issue mainly affects people who registered as self-employed between 2015 and early 2024. Many already had a Unique Taxpayer Reference and started trading without separately completing the CWF1 self-employment registration form. That happened even where they filled in the self-employed pages of their Self Assessment return correctly. The missing registration link meant HMRC’s systems didn’t always recognise that Class 2 National Insurance Contributions were due.

A couple of other things can also cause National Insurance gaps:

• Paying Class 2 contributions after the 31 January deadline
• Having a payment go toward an outstanding tax bill first, rather than National Insurance

HMRC has confirmed it fixed the underlying registration issue from 2024-25 onwards. It shouldn’t affect anyone starting out now. HMRC is contacting those closest to State Pension age first — roughly 160,000 people — with more letters to follow over the coming months.

Do you need to do anything?

Not urgently, and not just because a letter arrived. Most people need 35 qualifying years for the full new State Pension. You need at least 10 to get anything at all. Some people already have enough qualifying years from employment or earlier self-employment, so there’s nothing to fix. The sensible first step is simply to check, rather than assume you need to pay anything.

How to check your National Insurance record

The quickest way is via your Personal Tax Account on the HMRC website. It shows your State Pension forecast and your full National Insurance contributions history.

One thing worth knowing: we can’t log into your Personal Tax Account on your behalf. HMRC doesn’t allow agents to view a client’s PTA or pension forecast directly. We can help you set one up, though, and talk through what any gaps mean once you can see them. It’s also worth checking your record for National Insurance credits, for example for caring responsibilities — missing credits are a common cause of an incomplete record.

If you have a genuine National Insurance gap

If your check shows a shortfall, you can usually fill it with voluntary Class 2 National Insurance Contributions, provided it would actually improve your pension. This exercise is unusual: HMRC will let you fill gaps back to 2015-16. That’s well beyond the normal six-year window for voluntary top-ups. Class 2 contributions are relatively inexpensive for many self-employed people, so a genuine gap is often worth topping up — it’s one of the more cost-effective ways to improve your future State Pension.

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Not sure what your letter means?

If you’re self-employed and unsure whether your National Insurance gaps are worth acting on, we’re happy to talk it through. We build this kind of check into the wider support we give clients through Self Assessment and ongoing bookkeeping. Get in touch for a free, no-obligation chat →

This article provides general guidance only. For official detail see HMRC’s letter and your Personal Tax Account, or speak to a qualified bookkeeper.