Filing your Corporation Tax return late or getting your CT600 wrong can cost your business thousands in HMRC penalties and interest. As trusted, ACCA-regulated accountants in Slough, Direct Assist Accountants takes the stress out of Corporation Tax — accurate calculations, on-time filing, and every legal relief claimed, so your limited company stays compliant and pays only what it owes.
Every UK limited company must calculate, file, and pay Corporation Tax correctly — but the rules aren't simple. Since the rate structure changed to a 19% small profits rate, a 25% main rate, and Marginal Relief in between, many Slough business owners overpay, underclaim reliefs, or miss the CT600 filing deadline (12 months after your accounting period ends) and the payment deadline (9 months and 1 day after year-end).
Get it wrong and HMRC penalties start immediately — even a short delay can mean automatic fines, and repeated errors invite closer HMRC scrutiny. As experienced Corporation Tax accountants in Slough, Direct Assist Accountants handles the entire process for you: from calculating your liability correctly first time, to claiming every allowance you're entitled to, to submitting your return well before the deadline — so you can focus on running your business, not chasing paperwork.
If you run a UK limited company — of any size, in any industry — you're legally required to file a Corporation Tax return every year. Our Corporation Tax accountants in Slough support:
accurate corporation tax return prepared and submitted directly to HMRC
including correct application of Marginal Relief where it applies
we track your filing and payment deadlines so you're never caught out
capital allowances, R&D relief eligibility checks, and allowable expense optimisation
we deal directly with HMRC on your behalf if queries arise
proactive guidance, not just once-a-year filing
a clear quote upfront, no surprise bills
The main rate is 25% for profits over £250,000, and 19% for profits under £50,000 (the small profits rate). Companies with profits between £50,000 and £250,000 pay a tapered rate through Marginal Relief. Our accountants in Slough calculate your exact liability based on your specific numbers.
Corporation Tax must be paid 9 months and 1 day after your company’s accounting period ends. Your CT600 return itself must be filed within 12 months of the period end — but paying and filing are separate deadlines, and missing either can trigger HMRC penalties.
HMRC applies an automatic £100 penalty for late filing, rising further the longer the delay continues, plus interest on any unpaid tax. Persistent late filing can also increase your risk of an HMRC compliance check.
Yes. As experienced accountants in Slough, we handle HMRC correspondence and enquiries directly on your behalf, working to resolve investigations efficiently and minimise any additional liability.
Yes. Whether you’ve just incorporated or are switching from another accountant, we get your Corporation Tax position set up correctly from day one, including registering your company for Corporation Tax with HMRC.
Yes — Direct Assist Accountants is ACCA-regulated and a registered Companies House Authorised Corporate Service Provider (ACSP), giving you confidence that your Corporation Tax affairs are handled to professional UK standards.
Our team is part of Direct Assist Accountants' ACCA-regulated practice in Slough
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