HMRC offers an online service to check your National Insurance Contributions (NIC) record online. In order to use the service, you will need to have a Government Gateway account. If you don't have an account, you can apply to set one up online.

By signing in to the 'Check your National Insurance record' service you will also activate your personal tax account if you have not previously done so. HMRC’s personal tax account can be used to complete a variety of tasks in real time, such as claiming a tax refund, updating your address and completing your Self-Assessment return.

Your National Insurance record online will let you see:

In some circumstances it may be beneficial, after reviewing your records, to make voluntary NIC contributions to fill gaps in your contributions record to increase your entitlement to benefits, including the State or New State Pension. 

Source:HM Revenue & Customs | 11-09-2023