Episode 003 — When and How Corporation Tax Is Paid in the UK Corporation Tax is usually paid before the tax return is filed. This episode explains when Corporation Tax is due, how the nine months and one day rule works, when quarterly instalment payments apply, how long and short accounting periods affect payment, what happens if tax is paid late, how repayments work, and how Corporation Tax must be paid. As at September 2025. Educational content only. Full episode on YouTube: https://youtu.be/Z