Services
Corporation tax returns and planning before the year closes
We prepare your company's corporation tax computation and CT600 return from the year-end accounts, and review reliefs and timing while there is still time to act on them.
In short
Corporation tax is charged at 19% on profits up to £50,000 and 25% on profits over £250,000, with marginal relief in between. It is payable nine months and one day after the year end; the CT600 return is due twelve months after it.
What the service includes
- The corporation tax computation: adjusting accounting profit for disallowable costs, capital allowances and any losses brought forward.
- Capital allowances claims, including the Annual Investment Allowance of up to £1 million a year on qualifying plant and equipment.
- The CT600 return and the tagged accounts filed with HMRC through recognised software.
- A clear statement of the tax payable and the date it is due, sent well before the payment deadline.
- A pre-year-end review of reliefs, timing and how profits will be extracted.
How the rates work
| Taxable profits | Rate |
|---|---|
| Up to £50,000 | 19% (small profits rate) |
| £50,001 to £250,000 | 25%, reduced by marginal relief (an effective marginal rate of 26.5% within this band) |
| Over £250,000 | 25% (main rate) |
The £50,000 and £250,000 limits are divided by the number of associated companies and reduced for accounting periods shorter than twelve months. A second company under common control can push both companies into higher rates. It is one of the most common surprises we see.
Planning that happens before the year end, not after
By the time accounts are prepared, most decisions are fixed. We look at the position two to three months before the year end, covering:
- The timing of capital expenditure to use allowances in the right year.
- Employer pension contributions, which are generally deductible for the company when paid.
- The balance between salary and dividends, which changed materially in April 2026.
- Any overdrawn director's loan account, which can trigger a temporary additional tax charge if not cleared within nine months of the year end.
Larger companies
Companies with taxable profits above £1.5 million (divided between associated companies) pay corporation tax in quarterly instalments during the year rather than nine months after it. If growth is taking you towards that level, we plan the cash impact in advance through management accounts and forecasting.
Common questions
Questions we are often asked
The small profits rate is 19% on taxable profits up to £50,000. Profits above £250,000 are taxed at 25%, and profits in between are taxed at 25% reduced by marginal relief. The limits are shared between associated companies.
For most companies, nine months and one day after the end of the accounting period. The CT600 return is due twelve months after the end of the period. Companies with profits over £1.5 million pay in quarterly instalments instead.
Yes. A company that has been asked to file must file a return even if it made a loss or owes no tax. Filing also records the loss so it can be set against future profits.
Marginal relief reduces the 25% rate for companies with profits between £50,000 and £250,000, so the tax rate rises gradually rather than jumping. In practice, profits within that band are taxed at an effective marginal rate of 26.5%.
Contact
Bring us last year's accounts and we'll tell you what we'd change.
An initial conversation takes half an hour and costs nothing. If we are not the right practice for you, we will say so.