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Filing and payment dates
CT600 is due 12 months after your accounting period ends. Corporation Tax is payable 9 months and 1 day after the period end — so tax is due before the return itself. Plan your cash accordingly.
The rates from April 2023
- Profits up to £50,000 — 19% (small profits rate).
- Profits above £250,000 — 25% (main rate).
- Profits between £50,000 and £250,000 — marginal relief applies (effectively 26.5% on the slice).
Reliefs worth claiming
- Annual Investment Allowance — 100% first-year relief on plant & machinery up to £1m.
- R&D tax relief — for companies carrying out qualifying development, now on the merged scheme.
- Loss relief — carry trading losses back 1 year, forward indefinitely.
See our CT600 service for fixed-fee preparation and HMRC submission.