Corporation Tax,
optimised.
CT600 filing, reliefs optimisation, and proactive year-round corporation tax planning for UK limited companies.
What Is Corporation Tax?
Corporation tax is charged on the profits of UK limited companies and some other organisations. Every limited company must calculate its corporation tax liability, file a CT600 return with HMRC, and pay any tax due — within strict deadlines after each accounting period.
But corporation tax is not just a compliance obligation — it is an area where expert planning can significantly reduce your tax bill. With the right advice on reliefs, allowances, and timing, many companies pay substantially less than their initial calculations suggest.
Our Corporation Tax Service
We prepare the CT600 corporation tax return and the supporting tax computation, starting from your annual accounts and adjusting for items that are treated differently for tax purposes. This includes adding back disallowable expenditure and deducting qualifying reliefs. We review every available capital allowance claim — including the Annual Investment Allowance and any super-deduction or full expensing claims available for the period — to ensure you are not overpaying through an incomplete computation.
Where a company's activities may qualify for Research and Development tax credits, we assess eligibility and prepare the R&D claim as part of the corporation tax return. R&D credits can be substantial, and many companies carry out qualifying activities without realising it. We also consider deferred tax positions, particularly where timing differences arise between the accounts and the tax computation, and advise on quarterly instalment payment obligations for larger companies.
Beyond filing, we liaise directly with HMRC on any queries or enquiries into your corporation tax returns. HMRC has 12 months from the filing date to open an enquiry into a return, and having us as your agent means any correspondence is dealt with promptly and professionally. We also provide year-round tax planning advice to ensure your corporation tax position is managed proactively, not just addressed at year-end.
Why Choose Brathwaite?
CT600 corporation tax return filed accurately and on time
Full review of all available reliefs — R&D credits, capital allowances, and more
Year-round proactive planning, not just year-end filing
Dividend and director salary optimisation advice
Group structure and associated company considerations
HMRC correspondence and queries handled on your behalf
Frequently Asked Questions
When is corporation tax due?
Corporation tax is due 9 months and 1 day after the end of your company's accounting period. For example, if your year-end is 31st March 2025, corporation tax is due by 1st January 2026. Large companies may have different payment schedules. We ensure you are always aware of upcoming deadlines.
What is the current corporation tax rate?
From April 2023, UK corporation tax rates are 19% for profits up to £50,000 (small profits rate) and 25% for profits over £250,000 (main rate). For profits between these thresholds, marginal relief applies. We calculate your liability precisely and advise on strategies to optimise your tax position.
What reliefs can I claim?
UK companies can claim a range of corporation tax reliefs including: capital allowances on plant and machinery, research and development (R&D) tax credits, trading loss reliefs, and patent box relief. Many businesses are unaware of R&D credits they qualify for — we review your activities thoroughly.
Do I need to file if the company made a loss?
Yes. You must file a CT600 corporation tax return even if your company made a loss, had no activity, or owes no tax. Failure to file results in automatic penalties regardless of profitability. We handle this as part of your annual accounts service.