Service
Corporation Tax Returns
Corporation tax return and CT600 filing support for UK limited companies, directors and owner-managed businesses. Fixed fee agreed up front, ACCA-regulated.
Overview
CT600 filing support for limited companies
A corporation tax return is a CT600 filed with HMRC by UK limited companies after each accounting period. It reports taxable profit, reliefs and Corporation Tax due. The CT600 is due 12 months after period end, while payment is usually due 9 months and 1 day after period end.
A corporation tax return is the formal CT600 submission a UK company sends to HMRC after each accounting period. Countify prepares the CT600, tax computation and supporting checks so directors understand the taxable profit, reliefs claimed, Corporation Tax due and payment deadline before anything is filed.
Primary sources: Corporation Tax (HM Revenue & Customs), Running a limited company (GOV.UK) and Companies House (Companies House).
What you get
What a CT600 includes
The CT600 summarises your company's taxable profit, Corporation Tax charge, reliefs, losses, loans to participators, associated company position and other disclosures HMRC needs. It must agree with the statutory accounts and the detailed tax computation, so the work is not just form filling. We review the accounts, adjust for tax rules and explain the result before submission.
Key benefits
CT600 preparation and online submission to HMRC
Corporation Tax computation checked against statutory accounts
Clear deadline reminders for filing and payment dates
Review of losses, reliefs, director loans and associated companies
Fixed-fee support from an ACCA-regulated accountancy practice
How we deliver it
Corporation Tax Returns, step by step.
This is the workflow your job runs through in our practice system — the same stages, the same checks and the same deadline tracking for every client.
- Statutory deadline
- Corporation Tax is payable 9 months and 1 day after the period ends; the CT600 return is due 12 months after it.
- How we schedule it
- Scheduled five months after your year end — four months before the tax falls due, so you know the bill well in advance.
- 1
Preparation
Tax computation built from the approved accounts, with reliefs and allowances claimed where due.
- 2
Your approval
The computation is reviewed, then sent to you to approve before submission.
- 3
Filing
CT600 submitted to HMRC and the payment date confirmed to you.
Usually delivered alongside
Why choose Countify
Corporation Tax Returns, done right.
Countify supports limited-company directors who want corporation tax handled accurately, explained clearly and filed on time. We connect the CT600 to your accounts, bookkeeping and director tax position, then give you practical next steps for payment planning, marginal relief and future tax reserves.
Detail
Who must file a limited company tax return?
A UK limited company must usually file a CT600 when HMRC sends a notice to deliver a company tax return. That applies whether the company is profitable, loss-making, dormant for part of the year or expecting no tax to pay. Directors remain responsible for filing on time, even when an accountant prepares the return.
Limited companies trading in the UK.
Companies with investment income or chargeable gains.
Companies that made a loss but still received a notice to file.
Companies claiming reliefs, losses or allowances.
Companies with director loans or associated-company issues.
Detail
Corporation tax filing deadline and payment date
The filing and payment dates are different. The CT600 is normally due 12 months after the accounting period ends, but Corporation Tax is usually payable 9 months and 1 day after the period end. That means the tax bill often falls due before the return deadline.
- 9 months + 1 day
- Corporation Tax payment deadline for most small companies.
- 12 months
- CT600 filing deadline after the end of the accounting period.
- Quarterly instalments
- Large and very large companies may need to pay Corporation Tax earlier by instalments.
Detail
Penalties, marginal relief and tax planning context
Late CT600 filing can trigger automatic HMRC penalties, while late payment creates interest. The tax calculation itself also needs care: companies may pay 19%, 25%, or an effective rate through the marginal relief band depending on profits and associated companies. We review these points before filing so directors know what is being submitted and why.
Check whether small-profits rate, main rate or marginal relief applies.
Review associated companies before thresholds are applied.
Identify allowable expenses, capital allowances and loss claims.
Flag director loan account and close-company disclosures.
Explain payment planning before HMRC interest becomes an issue.
How we work
Predictable, fixed-fee engagements.
Corporation Tax Returns starts with a free discovery call. From there, we agree the scope and fixed fee upfront, so there are no surprises on your invoice. Once instructed, we deal directly with the relevant records, authorities and software access needed for this service.
- Step 01
Free discovery call
A 20-minute chat to understand your corporation tax returns needs, deadlines, and current records.
- Step 02
Fixed-fee proposal
We confirm the corporation tax returns scope and price in writing through an engagement letter.
- Step 03
Onboarding & delivery
We collect the information needed for corporation tax returns and keep each agreed deadline visible.
For corporation tax returns, we support clients in Glasgow city centre, across Scotland, and throughout the UK via Xero, QuickBooks Online, FreeAgent and secure document sharing. Day-to-day contact is with your named accountant.
Pricing
Fixed monthly fees
- Sole trader package
- from £35/month
- Limited company package
- from £95/month
Prices vary with scope and the state of your records. Your fixed fee is agreed in writing before any work starts. Corporation Tax Returns is quoted as part of that fixed fee or as an add-on.
See full pricing
Your accountant
Founder & CEO · Fellow Chartered Certified Accountant
Usually replies within one working day · Mon–Fri, 9am–5pm
5.0 on Google · 8 reviews- ACCA regulatedFirm no. 4549994
- AML supervisedby ACCA
- ICO registeredZA683204
- Companies HouseSC589649
Useful next steps
Related support
for this work.
What is a corporation tax return?
A corporation tax return is the CT600 form and supporting tax computation a UK company files with HMRC to report taxable profit, reliefs and Corporation Tax due for an accounting period.
Who must file a company tax return?
Most UK limited companies and other organisations within Corporation Tax must file a company tax return when HMRC issues a notice to deliver one, even if the company made a loss or has no tax to pay.
When is the CT600 filing deadline?
The CT600 filing deadline is normally 12 months after the end of the accounting period. The Corporation Tax payment deadline is usually earlier: 9 months and 1 day after the period end for most small companies.
What happens if a corporation tax return is late?
HMRC charges automatic late-filing penalties, with further penalties if the return remains outstanding. Late payment can also trigger interest. Repeated late returns increase the penalty level.
Can Countify help with a corporate tax return if the year has already ended?
Yes. We can prepare accounts, calculate Corporation Tax, file the CT600 and review deadlines even after the year has ended. Directors sometimes call this a corporate tax return; HMRC calls it a Corporation Tax return or CT600.
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Free, no-obligation consultation. We agree the fee upfront — no surprises.
5.0 on Google · 8 reviews- Fixed fee agreed in writing before work starts — no surprise bills.
- Switching is handled for you, including the professional clearance letter.
- A named accountant who knows your business, not a call queue.