The issue mainly affects individuals who registered as self-employed between 2015 and 2024 but were not correctly linked to HMRC's national insurance system.

This may have happened for a number of reasons. For example, an individual who already had a unique taxpayer reference (UTR) when they started self-employment may not have completed the required CWF1 form to register for self-employed national insurance. Alternatively, they may have paid voluntary Class 2 national insurance contributions (NICs) after the usual 31 January deadline, with the payments used to clear outstanding tax liabilities rather than being allocated to NICs.

Normally, voluntary NICs can only be paid for the previous six tax years. However, HMRC is relaxing this restriction for individuals affected by this issue. This means that eligible taxpayers may be able to make voluntary Class 2 NICs to fill gaps dating back to the 2015-16 tax year.

HMRC estimates that around 800,000 taxpayers could be affected.

HMRC will contact individuals it believes may be affected and provide information about the steps they can take. If you receive a letter from HMRC about missing national insurance years, we can help you understand whether you are affected, review your national insurance record and consider whether making additional contributions could help protect your entitlement to future state benefits, including the state pension.

If you think you may have gaps in your national insurance record but have not yet heard from HMRC, please get in touch and we can discuss your circumstances.