CT600 returns · Small UK limited companies
Corporation Tax returns for UK limited companies
Practical help with Corporation Tax calculations, CT600 returns and HMRC filing. Tell us your accounting period and the support you need; we’ll confirm the work, fee and next steps.
- Tax calculations based on your company’s records
- Eligible expenses, allowances and reliefs reviewed
- Scope, fees and filing responsibilities agreed upfront
A return or payment deadline approaching? Include the date in your enquiry so we can assess the work and availability.
Clear support with your company’s tax return
We review your accounting records and tax position before agreeing the work. You will know which calculations, returns and submissions are covered by your quote.
Corporation Tax calculations
Work from your accounts to calculate taxable profits or losses, reviewing business expenses, capital allowances and relevant reliefs against the rules.
CT600 preparation and filing
Prepare the Company Tax Return and agreed supporting documents using suitable commercial software, with your review and approval before submission.
Payment and deadline guidance
Explain the tax calculation and the filing and payment dates that apply. Filing a return and paying the tax are separate steps.
Need annual accounts as well? Your quote will confirm whether accounts preparation is included or whether we will use accounts prepared elsewhere. Bookkeeping catch-up, amendments, specialist relief claims and HMRC enquiry work are scoped separately where needed. Explore our company accounts service or R&D tax relief support.
A straightforward process
- Tell us what needs filing
Share your accounting period, the state of your records and any HMRC deadlines or outstanding returns.
- Agree the work and fee
We review your requirements and confirm the scope, information needed and proposed timetable.
- Review your tax calculation
We work through the records, resolve questions and explain the return for your approval.
- File and plan the payment
We complete the agreed submission and explain the tax payable, payment deadline and any remaining actions.
Client feedback on tax filings and support
“Responsive, diligent and pleasant to deal with, both with tax filings and ad hoc queries. Highly recommended!”
Fraser Burlingham
Corporation Tax questions before you enquire
Does my company need a Company Tax Return?
If HMRC sends a notice to deliver a Company Tax Return, you normally need to file even if the company made a loss or has no Corporation Tax to pay. Dormant companies and companies with no taxable profits may have different obligations; do not assume a nil tax bill removes a notice to file. Check HMRC’s Company Tax Return guidance.
When do I need to file and pay Corporation Tax?
The normal return deadline is 12 months after the Corporation Tax accounting period ends. Companies outside the instalment-payment rules normally pay tax nine months and one day after that period ends. Larger companies may need to pay earlier in instalments. First accounts covering more than 12 months can require two returns. We will check your company’s dates. Read HMRC’s instalment-payment guidance.
Which Corporation Tax rate applies?
The main rate is 25%, with a 19% small profits rate for eligible companies. Marginal Relief may apply between the relevant profit limits. Associated companies, short accounting periods and other eligibility rules affect the calculation. We assess your circumstances rather than assuming one rate applies to every small company. See HMRC’s current rates and conditions.
What records will you need?
We will confirm the list for your company. It typically includes annual accounts or a trial balance, bookkeeping records, bank statements, asset purchases, payroll information, director transactions and previous tax returns. Tell us about losses, group or associated companies, and any HMRC correspondence relevant to the work.
Can you prepare my annual accounts too?
Yes, we can discuss preparing your annual accounts alongside the Corporation Tax return. The quote will state the services and filing responsibilities agreed. Companies House accounts and an HMRC Company Tax Return have different requirements and deadlines. See our year-end accounts support.
How are Company Tax Returns filed now?
The joint HMRC accounts and Company Tax Return service closed on 31 March 2026. Company Tax Returns are now generally filed using commercial software, with limited exceptions. Companies House filing remains a separate requirement. Read HMRC’s current filing guidance.
Can you help with a late return or an HMRC enquiry?
Contact us with the notice or deadline and an outline of the issue. We will assess the work, availability and whether specialist support is needed before agreeing a scope. We cannot promise to remove penalties, secure a relief or resolve an enquiry without reviewing the circumstances.
Get your company’s tax return organised
Tell us what needs attention and we’ll discuss the next steps.