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HMRC Recognised CT600 Corporation Tax Gateway

File Your CT600 Corporation Tax Return Online

Calculate company tax, generate full iXBRL computations, and submit your CT600 directly to HMRC online. Take control of your company accounts and save thousands in accountancy fees.

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DIY Corporation Tax Filing for UK Limited Companies

Every UK limited company must file a Company Tax Return (Form CT600) with HMRC every year, even if your business made a loss or has zero tax to pay.

Traditional accountants often charge between £600 and £1,500+ just to file a standard micro-entity CT600. With Simply Accounts, you can prepare and file your own CT600 directly to HMRC for a fraction of that cost.

Simply Accounts guides you through every step: entering your turnover, cost of sales, administrative expenses, capital allowances (AIA), and losses brought forward. It automatically computes your corporation tax liability and compiles the mandatory iXBRL accounts and tax computations required by HMRC.

Simply Accounts CT600 Annual Accounts Screen
Simply Accounts Statutory Accounts & Corporation Tax Computation Generator

Key Features for Corporation Tax Compliance

Automated Tax Computations

Calculates taxable profits, adjusting for disallowable expenses, depreciation, and capital allowances automatically.

Inline XBRL (iXBRL) Generation

HMRC rejects plain PDF filings. Simply Accounts automatically embeds standard UK GAAP / FRS 105 iXBRL tags seamlessly.

Capital Allowances & AIA

Easily claim Annual Investment Allowance (AIA), first-year allowances, and write down plant and machinery balances.

Trading Losses Handling

Carry trading losses back to earlier accounting periods or forward against future trading profits effortlessly.

Direct HMRC Gateway Filing

Submit directly to HMRC using your Government Gateway credentials. Receive instant submission confirmation and correlation ID.

Dual Filing with Companies House

Fulfill both statutory obligations at once: file your CT600 with HMRC and submit micro-entity accounts to Companies House.

File Your CT600 for Just £60 p.a. + VAT

No expensive accountancy retainers. Includes full CT600 filing, Companies House submission, cash book, and year-end accounts.

£60 p.a. + VAT (Single Company)

Need to manage multiple companies? Unlimited companies edition is just £120 p.a. + VAT.

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Frequently Asked Questions About CT600 Filing

Can I file my own CT600 return without an accountant?

Yes. Company directors are legally entitled to prepare and file their own Corporation Tax return (CT600). Simply Accounts automates the tax computations, capital allowances, and required iXBRL tags so you can submit directly to HMRC.

Does Simply Accounts produce the iXBRL accounts and computations required by HMRC?

Yes. HMRC mandates that CT600 submissions include computations in inline XBRL (iXBRL) format. Simply Accounts generates this automatically behind the scenes.

Does the software also submit accounts to Companies House?

Yes. Simply Accounts Final Accounts edition handles both HMRC CT600 tax returns and Companies House micro-entity statutory accounts and Confirmation Statements (CS01).

What is the deadline for filing a CT600 return?

Your Company Tax Return (CT600) must be filed with HMRC within 12 months of the end of your company's accounting period. Note that any Corporation Tax owed must typically be paid earlier: 9 months and 1 day after the end of the accounting period.

Start Your Company Tax Return Today

Download our free 14-day trial and see how easy it is to file your CT600.

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