A practical record-keeping checklist so you can derive a reliable annual profit figure for estimates and filing.
Aim to explain your annual income, your main business costs, and how you arrived at profit for the tax year. A basic system is better than no system.
This tool expects profit after allowable expenses. If you can produce a profit summary for the year, you can use the calculator confidently.
Mixing personal spending with business costs, losing invoices, and relying on memory. Build a routine and keep evidence.
Not tax advice. This page is an educational guide. For official rules, verify the sources below.
Last updated: 2026-04-20
Not necessarily. Many people start with a spreadsheet and upgrade later.
Track each stream and then roll up to an annual profit figure if that matches your filing.
No. Use GOV.UK for the authoritative requirements.
For official rules and definitions, verify with the references below.