How much does it cost to file a CT600 in 2026?

In short: Filing a CT600 costs whatever your software or accountant charges, because HMRC's free online filing service closed on 31 March 2026 (GOV.UK: Closure of HMRC's file-your-accounts-and-tax-return service). On 24 September 2026, software that prepares the accounts, computation and CT600 for a micro-entity trading company was published at £20 to £166.80 a return, or £0 through one bookkeeping product for customers of certain business bank accounts. Taxley charges £9.50 (promotion price until 31 Dec 2026; £19.00 from 1 Jan 2027) for a dormant company, £44.50 (promotion price until 31 Dec 2026; £89.00 from 1 Jan 2027) with micro-entity accounts and £84.50 (promotion price until 31 Dec 2026; £169.00 from 1 Jan 2027) with small-company accounts, including filing the accounts at Companies House.

For what each type of CT600 software prepares and who it suits, see our guide to choosing CT600 filing software. Taxley publishes this guide and sells CT600 software: take the 30-second check to see whether Taxley fits your company.

How much does it cost to file a CT600 in 2026?

The cost of filing a CT600 in 2026 depends on which of three routes you use and how much of the return you prepare yourself. HMRC says companies should now file using commercial software, and that the software should cover the CT600, the Corporation Tax computation and the company accounts (GOV.UK: Closure of HMRC's file-your-accounts-and-tax-return service).

The three routes are CT600-only software, when you already have accounts and a computation; all-in-one software, which prepares all three from your figures; and an accountant, who prepares and files for you. Every route sits alongside two Companies House filings with their own costs: annual accounts, which carry no Companies House fee, and the confirmation statement, which costs £50 online (GOV.UK: Companies House fees). The table puts the three routes side by side using prices published on 24 September 2026.

Figures checked on 24 September 2026 on GOV.UK and on each supplier's own website. Prices include VAT where the supplier states its VAT treatment; several low-cost products don't state it on their pricing pages.

Is there free CT600 software now HMRC's service has closed?

There's no longer a free HMRC online service for filing a CT600, and of the products we checked on 24 September 2026, only one had a £0 route for a trading company, with conditions attached. HMRC's "File your accounts and Company Tax Return" service closed on 31 March 2026, a closure announced on 6 March 2025 (GOV.UK: The online accounts and Company Tax Return service is closing).

HMRC accepts a paper Company Tax Return only if you have a reasonable excuse or are filing in Welsh (GOV.UK: Closure of HMRC's file-your-accounts-and-tax-return service). That route was bookkeeping software that prepares FRS 105 micro-entity accounts and the CT600 from your records, free for customers of certain business bank accounts; otherwise it's a monthly or yearly bookkeeping subscription. Most of the other products we checked, Taxley included, let you prepare and preview a return free and charge only when you file.

Our guide to choosing CT600 software now HMRC's service has closed lists the questions to ask before you pay. If you used HMRC's old service, File company accounts and tax return online now CATO has closed covers what Taxley files instead.

What is the cheapest way to file a CT600 for a small limited company?

The cheapest way to file a CT600 for a small limited company is to use the lowest-priced software that fully covers your company's accounts and tax position, and to file on time. For a micro-entity trading company, the gap between the cheapest price with Companies House filing (£20) and the dearest (£166.80) we found was £146.80, less than one £200 late-filing penalty (GOV.UK: Company Tax Returns: Penalties for late filing).

Some low-priced products, including the subscription products we checked, handle micro-entity (FRS 105) accounts only, so a company over the micro-entity limits has fewer options: among products that state FRS 102 support, published prices for FRS 102 Section 1A small-company accounts ran from £25 to £195 + VAT. Check whether each price includes VAT, Companies House filing and amendments, and whether it's a yearly subscription or a fee per return. Filing it yourself is covered step by step in how to file a CT600 yourself.

Our guide to micro-entity and small-company accounts explains which your company needs.

What does Companies House charge when you file accounts?

Companies House charges no fee to file annual accounts: its WebFiling fee table lists annual accounts and dormant company accounts as "No fee" (Companies House: Companies House WebFiling Help and Support). The Companies House fee you pay each year is for the confirmation statement: £50 when filed online or through software, or £110 on paper (GOV.UK: Companies House fees).

Accounts are a separate filing from the CT600, with an earlier deadline: a private company has 9 months from the end of its accounting reference period to deliver them (GOV.UK: Preparing and filing Companies House accounts), against 12 months for the CT600 (GOV.UK: Company Tax Returns: Overview). Some CT600 products file your accounts to Companies House as part of the price. Taxley is one of them. Others don't, so you file the accounts yourself. From 1 April 2028, accounts can only be filed with Companies House using commercial software, as our guide to software-only accounts filing from 2028 explains.

How much does an accountant charge to file a CT600?

We haven't found a credible published survey of what UK accountants charge to prepare and file a small company's CT600, so this guide doesn't quote a fee range. The figures on accountancy firms' own websites are sales estimates, not surveys.

An accountant's fee depends on how much work your company needs: the state of the bookkeeping, whether the accounts are micro-entity or small-company accounts, the number of transactions, a director's loan that needs a CT600A (see the CT600A and section 455 tax), capital allowances or asset sales, losses, a first period longer than 12 months, and whether the quote also covers Companies House filing, the confirmation statement, payroll or the directors' personal tax returns. Ask for a fixed quote that lists each item, then compare it with the cost of filing yourself with software. Our do I need an accountant? page sets out which returns still need one.

What does it cost if you file or pay late?

HMRC's first £200 late-filing penalty costs more than every per-return price we found for a micro-entity trading company (£20 to £166.80). HMRC charges £200 once a CT600 is late and another £200 at 3 months; if a return is late 3 times in a row, each £200 becomes £1,000 (GOV.UK: Company Tax Returns: Penalties for late filing).

On top of those, HMRC charges 10% of the tax still unpaid if the return is 6 months late (18 months after the accounting period ends), rising to 20% if it is 12 months late (2 years after the period ends) (GOV.UK: Company Tax Returns: Penalties for late filing).

Companies House charges a private company £150 for accounts up to 1 month late, rising to £1,500 after 6 months, and doubles the penalty if accounts are late 2 years in a row (GOV.UK: Penalties for late filing of annual accounts). Paying Corporation Tax late is charged separately: HMRC charges interest daily from the day after the payment deadline (normally 9 months and 1 day after the period end) until you pay (GOV.UK: Corporation Tax: interest charges). The rate has been 7.75% a year since 9 January 2026 (GOV.UK: HMRC interest rates for late and early payments), and HMRC doesn't charge interest on interest (GOV.UK: Corporation Tax: interest charges).

Worked example: a private micro-entity company's accounting year ends on 31 March 2026 (not its first accounts) and it owes £5,000 of Corporation Tax. The tax is due by 1 January 2027, the accounts by 31 December 2026 and the CT600 by 31 March 2027. If the director files everything and pays the tax on 31 July 2027, the CT600 is 4 months late (£200 plus £200, so £400), the accounts are 7 months late (£1,500, assuming neither was late in earlier years), and 211 days of interest at 7.75% adds about £224, assuming the rate doesn't change. That's about £2,124 in total, against software prices of £20 to £166.80 for the same micro-entity return. Use the Corporation Tax deadline calculator to find your own dates, and see what happens if you file your CT600 late for appeals.

How much does Taxley charge to file a CT600?

Taxley charges one fee per return, with no subscription: £9.50 for a dormant company's nil return with dormant accounts, £44.50 for a CT600 with micro-entity (FRS 105) accounts, and £84.50 with small-company (FRS 102 Section 1A) accounts. The pricing page shows every price and when these promotion prices end.

Each fee covers the CT600, the Corporation Tax computation and the iXBRL accounts filed to HMRC, and filing the same accounts at Companies House. Against the dormant prices 12 other products published on 27 September 2026, Taxley's current dormant price is the 3rd-lowest of 13, and its small-company (FRS 102) price was the 2nd-lowest of 5 that publish an FRS 102 price. Preparing and previewing is free, and you pay only when you file. Accountants can buy prepaid practice packs, also shown on the pricing page. The fee also covers filing the accounts at Companies House, which you do from the filing page once the return is paid; Companies House charges no fee for them. Amending a return after HMRC has accepted it costs the standard fee for a return of that kind. Taxley doesn't cover every company, for example R&D relief claims or terminal loss claims, so take the 30-second check to see whether Taxley fits your company.

Frequently asked questions

How much does it cost to file a CT600 yourself?

Only the software fee. On 24 September 2026, software that prepares the accounts, computation and CT600 for a micro-entity trading company was published at £20 to £166.80 a return, and dormant nil returns started at £5. HMRC's free online service closed on 31 March 2026.

Is filing a dormant company's CT600 free?

Not through HMRC's own online service, which closed on 31 March 2026. Software prices for a dormant nil return started at £5 on 24 September 2026. You must file if HMRC sends a notice to deliver a return; our dormant company tax return guide explains when.

Does Companies House charge to file accounts?

No. Companies House lists annual accounts and dormant company accounts as "No fee". Its £50 yearly fee is for the confirmation statement filed online or through software (£110 on paper), which is a separate filing from the accounts.

Is an accountant cheaper than CT600 software?

It depends on the quote. Software fees in this guide ran from £5 to £195 + VAT a return, but you do the preparation yourself. An accountant's fee pays for their work and judgement, which matters more for returns with R&D claims, terminal loss claims or uncertain figures.

Is late payment interest on Corporation Tax tax deductible?

Yes. HMRC says late payment interest you pay is tax deductible for Corporation Tax, in the accounting period when the interest was incurred. It's charged at 7.75% a year since 9 January 2026, as simple interest.

General information, not personalised tax or accounting advice. Vendors change their prices: check each vendor's own pricing page before you buy.