You may have gaps, or part years in your National Insurance record for a number of reasons - you may have been self-employed, or working abroad, employed on low earnings or unemployed and not claiming benefits. You may have gaps in your record if you were “contracted out” and it’s worth first checking if you do have any gaps or part years by creating an online account: check-national-insurance-record. It is possible to top up your state pension entitlement by making voluntary contributions.