Corporation Tax Returns
Accurate CT600s, planned reliefs, and no nasty surprises in month nine.
Who this is for
Limited companies with profits between £50k and £10m where the difference between a 19%, 25% and marginal-rate calculation actually moves the dial.
Your corporation tax bill is a planning output, not a year-end shock.
By the time most companies see their corporation tax bill, the planning window is closed. We work the other way around — the CT liability is one of the things we model from month one of the year, so the number you see at year-end is the number you expected.
Our corporation tax service covers full CT600 preparation alongside your statutory accounts, but the value sits in the in-year work: capital allowances claims, R&D where relevant, loss utilisation, and how you take money out of the business as a director-shareholder.
What's included.
Everything below is part of the standard engagement. We'll tell you up front if your situation needs anything outside this — there are no surprises.
Full CT600 preparation, iXBRL-tagged and filed with HMRC
Capital allowances review (full expensing, AIA, special rate pool, structures and buildings)
R&D tax relief eligibility assessment and claim where applicable
Loss relief planning — group relief, carry-back, carry-forward
Director extraction strategy: salary / dividend / pension / benefits in kind
Quarterly CT estimate so you know what you owe before HMRC tells you
A predictable, four-step engagement.
In-year modelling
We project your taxable profit and CT liability quarterly, so the number is never a surprise.
Reliefs review
Before year-end we check capital expenditure, R&D activity and loss positions for opportunities.
CT600 preparation
Full computation prepared alongside your statutory accounts, with disclosures and adjustments documented.
Filing and payment plan
Return filed with HMRC, payment dates calendared, and any quarterly instalment payments scheduled.
Frequently asked questions
What is the corporation tax rate from April 2023 onwards?
Companies with profits over £250,000 pay the main rate of 25%. Profits up to £50,000 pay 19%. Between £50,000 and £250,000 there is a marginal rate calculation that effectively works out at around 26.5% on the band — which is why structuring the year matters.
Can you handle R&D tax relief claims?
Yes — we prepare R&D claims under both the merged scheme (for accounting periods beginning on or after 1 April 2024) and the previous SME / RDEC regimes for prior periods. We are deliberately conservative: we only claim what is genuinely qualifying, because HMRC enquiry rates are high and we do not want to drag clients into a fight they cannot win.
When is corporation tax due?
For most companies (profits under £1.5m), CT is payable 9 months and 1 day after the end of your accounting period. Larger companies pay in quarterly instalments. The CT600 return itself is due 12 months after the period end.
Related: explore the full services suite —All services
Talk to us about corporation tax.
Quick conversation, no commitment. We'll tell you honestly whether this is the right service for where you are.