Plain-English guides to UK Corporation Tax and CT600 filing.
Miss your CT600 deadline and HMRC charges escalating penalties — from £200 on day one for filing dates from April 2026, rising to 10% of unpaid tax. Learn the full penalty structure, appeal options, and how to file on time.
Missed your CT600 deadline? Learn the exact HMRC penalty structure — £200 initial then 10% and a further 10% for filing dates from April 2026 — how late payment interest works at 7.75%, and the steps to fix it fast. Plus how to appeal.
Full 2026 calendar of Corporation Tax deadlines — CT600 filing dates, payment due dates, penalty dates, and quarterly instalment dates month by month.
What are the penalties for filing your CT600 late? Understand HMRC penalty rates, interest charges, and how to avoid or appeal late filing penalties.
Got a CT600 late filing penalty? You may be able to appeal. Step-by-step guide to HMRC penalty appeals, reasonable excuses, and time limits.
Complete guide to CT600 late filing penalties and charges. How much you'll pay, when penalties apply, and how to appeal HMRC penalty decisions.