The cheapest way to file a CT600 in 2026: your options compared

By Max Szolcek, founder of Dormant Return. Last updated 2 October 2026

Since HMRC closed its free online service on 31 March 2026, every Company Tax Return has to go through commercial software or an accountant. For a company that owes no tax, that is a new bill for a return that is almost entirely zeroes. Here are the realistic routes, what each one costs, and what to check before you pay for any of them.

Why there is no free route any more

Until March 2026 a small company could file its accounts and its CT600 through HMRC's own online service at no cost. That service closed on 31 March 2026. HMRC's guidance now says that from 1 April 2026 you should use commercial software to file annual accounts and Company Tax Returns with HMRC, and that a paper return is only allowed if you have a reasonable excuse or are filing in Welsh. Not owing any tax does not change this: gov.uk is explicit that you must still send a return if you make a loss or have no Corporation Tax to pay.

Companies House is separate. Its own online filing for annual accounts continues, and dormant company accounts can still be filed there without paying for software. The background to the closure is in HMRC's free filing service has closed: your options.

The four routes

Route	Typical cost	Who it suits	What you do yourself	Watch-outs
An accountant	Varies widely; fees are quoted per firm and usually cover a year of work rather than one return	Companies that trade, have payroll or VAT, or need advice as well as a filing	Provide records, sign what you are sent	Paying professional rates for a nil return; the accountant may file as your agent rather than under your own Government Gateway sign-in
General Corporation Tax software	Roughly £80 to £100 or more per year	Trading companies with computations, reliefs, capital allowances or losses to carry	Prepare the accounts, the computation and every CT600 box	A yearly subscription for features a dormant company never touches; a steep form for a first-time filer
Dormant-company specialist services	Priced per return; check each supplier's own page	Companies that have never traded or have stopped trading	Confirm the company details and period, then approve	Some cover the CT600 only and leave you to source iXBRL accounts elsewhere; some need an account or a subscription
Dormant Return	£5 per dormant return; £15 for a small company that traded (loss, nil or a small profit); £5 for a charity or sports club whose income is all exempt	Dormant companies, including those holding cash or share capital; small trading companies with a loss, nil or a profit up to the small profits limit; charities and registered community amateur sports clubs claiming full exemption on page CT600E, with their own accounts attached as a PDF	Type the company name, confirm the period, sign in to the Government Gateway	Not yet on HMRC's recognised software list; accounts longer than 12 months are filed as two returns; profits above £50,000 or claims beyond the annual investment allowance need another route

The accountant and software figures are deliberately general. Accountancy fees are set firm by firm and depend on what else the firm does for you, so a single number would be misleading. The £80 to £100 band for general software is the price of packages built for accountants and trading companies; they will file a dormant return, but you are paying for computations, group relief and other features a company with nothing to report will never use. Our own prices are on the pricing page.

What "HMRC-recognised" means, and what it does not

HMRC publishes a list of commercial software suppliers for Corporation Tax. The publication says HMRC accepts returns filed using any of the products shown in it, and it does not recommend one product over another. The list groups suppliers by what their product can produce, and marks the ones suitable for people filing their own return rather than for accountants.

Three things follow from that. Recognition is not a licence: it is a listing, applied for by the supplier, and HMRC's own developer support team describes it as optional. Every product on or off the list submits through the same Government Gateway submission service, and HMRC validates every return in the same way. And a product's absence from the list says nothing about whether HMRC accepts its returns; it says the supplier has not yet been through the listing round, which for Corporation Tax opens once a year.

Dormant Return is not yet on that list. Its returns have been tested against HMRC's External Test Service, and every accepted filing comes back with HMRC's own receipt carrying the IRmark of the submitted return. We intend to apply when the next recognition round opens, and this page will change when that happens.

What to check before you choose

Are iXBRL accounts included? HMRC will not accept a CT600 without accounts tagged in iXBRL, even for a dormant company. A product that files the CT600 alone leaves you to find the accounts somewhere else. See dormant company iXBRL accounts explained.
Is a tax computation included where you need one? A company that traded, even at a loss, must file a computation as well as accounts. A dormant company does not. See company traded, loss or small profit: what to file.
Whose sign-in is used? Filing under your own Government Gateway credentials keeps you in control and means nobody else holds your company's HMRC access. An agent files under theirs.
What happens if HMRC rejects the return? Look for a refund policy that does not depend on chasing anyone.
Subscription or one-off? A dormant company files once a year. A rolling subscription for that is money spent on the other eleven months.

The five-minute route for a dormant company. Dormant Return prepares the CT600 and iXBRL dormant accounts and files them straight to HMRC under your own Government Gateway sign-in. £5 one-off, no account, refunded automatically if HMRC rejects the return. The walkthrough is in how to file a dormant company CT600 online.

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