UK Self Assessment Guide
A practical checklist for registration, records, filing and payment through HMRC Self Assessment.
Quick answer
Self Assessment is HMRC’s system for reporting income and gains not fully dealt with through PAYE. Check whether you need a return, register by the applicable deadline, maintain records and file using current HMRC guidance.
Preparation checklist
- Confirm whether a return is required for the tax year.
- Register or reactivate Self Assessment if necessary.
- Collect income, expense, pension, Gift Aid and capital-gains records.
- Reconcile figures before entering them.
- File and pay through an approved HMRC route.
Important dates
Registration, paper-filing, online-filing and payment deadlines are different. Payments on account may also apply. Verify the dates for the relevant tax year directly with HMRC.
After filing
Save the submission receipt and tax calculation, confirm payments have been allocated, and retain the records for the required period. Correct errors promptly using the current amendment process.
Educational information only: Rules and thresholds can change. Confirm current requirements with the relevant authority or a qualified professional before acting.
