Good to know
Clear guidance, in plain terms.
General information to help you understand this area — not personal advice. Rules, thresholds and deadlines can change, so check the latest HMRC guidance or ask us about your circumstances.
Filing and payment deadlines
A company must file its Company Tax Return (CT600) within 12 months of the end of its accounting period. Corporation Tax is generally payable earlier — nine months and one day after the end of the accounting period for companies with profits under the £1.5m threshold. Missing deadlines triggers automatic penalties and interest.
Reliefs and allowances
Companies can reduce their taxable profits through capital allowances on qualifying equipment, R&D relief for qualifying innovation, and other statutory reliefs. Claiming these correctly and on time is part of getting the return right.
Associated companies and groups
Where you control more than one company, the rules on associated companies and group relief can affect the rate and timing of tax — worth reviewing before decisions are made, not after.