You usually do not need to upload documents to check your State Pension forecast online. Have your National Insurance number, date of birth and personal details ready, along with the sign-in details for the GOV.UK service. If your National Insurance record appears incomplete or incorrect, documents such as P60s, payslips, employer letters or evidence of National Insurance credits may help when asking for it to be checked. Use the official GOV.UK State Pension forecast service or contact the Future Pension Centre if you need further guidance.