To qualify for a full state pension you need to have 35 years of National Insurance contributions. You can check your National Insurance record https://www.gov.uk/check-national-insurance-record . If there is likely to be a shortfall you can buy additional years by making Class 3 or in the case of the self employed Class 2 contributions. You can make additional contributions for the previous 6 years, although until April 2025 you can make backdated contributions to the 2006 -07 tax year.