You can check your State Pension forecast online through the official GOV.UK service, using your Government Gateway sign-in or personal tax account. It shows when you may reach State Pension age, how much you could receive, and whether you can improve your forecast through further National Insurance contributions. You can also review your National Insurance record online to identify missing years or gaps, although buying voluntary contributions is not always beneficial. For personalised guidance, contact the Future Pension Centre or check the latest information on GOV.UK.