Corporation Tax Calculator
Estimate what your company owes.
Since April 2023, corporation tax isn’t a single rate. Smaller profits still pay 19%, bigger ones pay 25%, and profits in between get marginal relief. This calculator handles all three cleanly.
Quick reference
How the two rates (and marginal relief) work.
The band depends on your taxable profit and whether you have associated companies.
-
Small profits rate
19%
Applies to taxable profit up to £50,000.
-
Main rate
25%
Applies to taxable profit of £250,000 or more.
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Marginal relief band
£50k–£250k
Profit in this range taxed at an effective rate between 19% and 25%.
-
Marginal relief fraction
3/200
The standard marginal relief fraction for the 2026/27 tax year.
-
Associated companies
Shared
Thresholds are divided by the number of associated companies.
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Payment deadline
9m + 1d
Corporation tax is due nine months and one day after year-end.
Calculation result
Total corporation tax due
£—
Where the tax comes from
Accounting period
—
- Net profit (turnover − expenses)
- —
- Pre-April 2023 (— days)
- £—
- at 19%
- £—
- Post-April 2023 (— days)
- £—
- at —%
- £—
- Total corporation tax
- £—
due by —
You’ve shown a loss. No corporation tax is due for this year. Losses can usually be carried forward to offset future profits, reducing your tax bill in profitable years.
Marginal relief applied. Your profit falls inside the marginal-relief band, so the effective rate sits between 19% and 25%. Pension contributions and other timing strategies can pull profit back under the small-profits threshold and lock in the 19% rate.
Bands divided across — companies. The standard £50,000 and £250,000 marginal-relief thresholds are split across all associated companies, so for your setup the small-profits rate applies up to £— and the main rate kicks in at £—.
Heads up: Corporation tax is due 9 months and 1 day after your year end — mark the date and set the cash aside.
Want help reducing this number? Book a free chat or call 020 7731 1117.
Three things to plan around.
A little foresight at year-end can knock thousands off the bill.
Time your expenses
Legitimate spending before year-end reduces taxable profit. Kit, training, subscriptions, pension contributions — all count.
Watch the £50k cliff
Just over £50k pushes you into marginal relief. Pension contributions are a common, clean way to bring profit back under the line.
Associated companies matter
If you run more than one company, the £50k and £250k thresholds split across them. Plan dividend and pension timing together.
Helpful to know
What is an “associated company”?
If you control more than one company, HMRC treats the corporation tax thresholds as shared across them.
In plain English
Two companies are associated when one controls the other, or both are under the control of the same person or group. This includes overseas companies — a Ltd you control in New Zealand or Australia counts just as much as a UK one.
Common examples:
- You run a contracting Ltd and a property Ltd.
- You and your spouse each have your own Ltd company.
- A holding company that owns a subsidiary.
Why it matters
The £50,000 and £250,000 corporation tax thresholds are divided across all associated companies.
For example, with 2 associated companies each gets:
- Small-profits rate (19%) up to £25,000
- Main rate (25%) above £125,000
- Marginal relief in between
Dormant companies usually don’t count, and a few other exemptions apply (passive holding companies, for example). We can check your specific setup.
More from Resources
While you’re here…
Dividend Tax Calculator
Work out the tax on dividends drawn from your limited company.
Umbrella Pay Calculator
See your weekly or monthly take-home through an umbrella.
Salary Calculator
Check take-home on any salary — tax, NI and pension factored in.
Software
Joy Pilot — included with every No Worries package.
Still not sure?
Let’s talk it through.
A calculator gives you the numbers. A five-minute call with us gives you the context. No sales pitch — just a clear answer.
Prefer to talk? Call us on 020 7731 1117