Your Company Tax Return, built from your books
TaxPip works out Corporation Tax from your reviewed books and sets it out as the boxes of the CT600, with the accounts and the computations, for you or your accountant to file. Sending it from TaxPip is planned, but it is not available.
To HMRCReturn 12 months after the period ends
Who needs it
A company files a Company Tax Return when HMRC sends it a notice to deliver one, and files it even when there is no tax to pay. The Company Tax Return guide explains the notice and what goes in the return.
The return is due 12 months after the end of the accounting period. The Corporation Tax itself is due nine months and one day after the period ends, so the money is due long before the return. The deadlines page shows how each date is worked out, and the Corporation Tax calculator estimates the tax before you start.
A limited company files the return online with commercial software: HMRC's own online service for it closed on 31 March 2026. The CT600 software guide says what to look for.
How it works here
Tax worked out from the books
The profit in the accounts is adjusted to the profit for tax at the rates in force for the period, with marginal relief where it applies. The rules do the arithmetic. The AI only suggests categories.
Set out as the CT600
The result is laid out as the boxes of the CT600, with the accounts and the computations that go with it, and checked against HMRC's published schema and rules.
Review and approve
An owner reads the figures and the checks the software ran, then approves the pack. Its files are locked from then on: what is sent is exactly what you approved.
File it, and keep the result
You, or your accountant, file the return with commercial filing software, using the step-by-step guide and the bundle of files in the pack, and record the result. Sending it from TaxPip is planned, but it is not available.
What to have ready
- The company's books for the accounting period, reviewed, and its accounts details.
- The company's Unique Taxpayer Reference (UTR).
- A way to file the return: commercial filing software, or your accountant.
What you will see once it is sent
Sending a filing from TaxPip is planned, but it is not available. When it is, every filing is saved before it is sent and followed until the authority has decided. These are the only states it can be in, and they only move forward.
Sending
Saved first, then sent. A crash cannot leave a filing that nobody has a record of.
Received
The authority has the message and has not decided.
Accepted
The authority has accepted it. The answer is kept with the filing.
Or it stops somewhere else
Rejected
The authority has said why not, and its reason is shown as it was sent.
Refused
The authority refused the message itself, so nothing was filed.
Unknown
The reply was lost, so there is no telling whether it arrived. It is never sent a second time by itself: you ask the authority, or say it never arrived.
What it covers, and what it does not
No capital allowances and no research and development relief.
The engine adds depreciation back and allows no capital allowances. If your company needs either, work them out first.
Computations for a period ending after 31 March 2026 are not tagged yet.
The pack still has the accounts, the CT600 values and the workings, and says so.
A new return only.
An amendment, a supplementary page and a PDF attachment are not sent from here.
A working draft.
No accountant has reviewed the calculations. Check the figures, or have them checked, before anything is sent.
Questions
Do I file a return if there is no tax to pay?
Yes, when HMRC has sent the company a notice to deliver a return, even if no tax is due. The company also pays, or tells HMRC none is due, by nine months and one day after the period ends.
Why does the tax computation say it is not tagged?
HMRC's taxonomy for computations does not yet cover a period that ends after 31 March 2026. The pack still holds the accounts, the CT600 values and the workings, and says that the computation is not tagged.
Who submits the return to HMRC?
You do, or your accountant. TaxPip does not send it: it gives you the pack, a step-by-step guide and a bundle of files. Sending it from TaxPip is planned, but it is not available.
Keep reading
- The Company Tax Return (CT600) explained
What a UK limited company's Company Tax Return (CT600) is, what goes in it, how its dates work, and what happens when it is late or wrong.
- Corporation Tax calculator for a UK company
Estimate a UK company's Corporation Tax for an accounting period: small profits rate, main rate, marginal relief and associated companies.
- Annual accounts for a UK micro company
Micro-entity (FRS 105) annual accounts built from your books and tagged in iXBRL, ready to file with Companies House. Free during early access.
Try it on your own books
Free during early access. An account takes an email address and a code: there is no password, no card to enter, and nothing is charged.