How to file a charity or CASC Corporation Tax return with CT600E

1. Choose the filing scope

Short version. A wholly exempt incorporated charity or CASC can file a CT600 with CT600E and its own accounts. This route is for a private limited company with a Companies House record and a period of accounts of up to 18 months. It files with HMRC only.

In step 1, Special tax regimes appears above What are you filing? Choose No for a standard UK trading or dormant company. When available, choose Charity or CASC for a full exemption claim. Choosing Charity or CASC selects HMRC CT600 and disables the Companies House choices. The answer declares that all income and gains are exempt and have been, or will be, applied for charitable or qualifying purposes. Do not select it for a partly taxable return or a charity-owned trading company. CIOs, SCIOs and unincorporated clubs are outside this service.

2. Complete the CT600E card

In step 2, open CT600E: Charity exemption claim or CT600E: CASC exemption claim, according to your step 1 answer. A charity can enter its Charity Commission or OSCR number if it has one. A CASC is not asked for a charity registration number. Either can enter its HMRC repayment reference. Use the income, expenditure and asset figures in your prepared accounts. Leave optional amounts blank if none. The card adds total income E90 and expenditure E125.

A legacy is a gift left in someone's will. Enter the total legacy income from your accounts in E88 and complete Date of the legacy. If there were several legacies, add them together and enter one total and the latest legacy date. For example, legacies of £2,000 and £3,000 mean entering £5,000 and the later date. For a long period requiring two returns, also follow the allocation steps below.

Asset labels change from amounts held at the period end to additions for periods starting on or after 1 April 2026. Changing dates keeps your figures so you can check them.

Qualifying investments and loans, E180, and non-qualifying amounts, E185, apply only to charities. Enter the number of controlled companies at E190, excluding companies dormant throughout the period. The tooltips link to the complete HMRC box guidance.

What if the accounts cover more than 12 months?

HMRC needs two CT600 returns because an accounting period for Corporation Tax cannot exceed 12 months. The first return covers 12 months and the second covers the remaining months. Each has its own CT600E. Enter your full-period figures once. We divide income, spending and disposal proceeds between the returns by days, using whole pounds. This is our service treatment of these information boxes, based on the usual time-apportionment approach. Check both returns before filing.

Asset balances are repeated. For returns starting on or after 1 April 2026, the relevant asset boxes instead report additions. If both returns use that meaning, we divide the full-period additions by days. If only the second return uses it, open Assets added during and enter additions for the dates shown. You can open this group even with zero closing balances.

For legacy income, use Amounts across your two returns to allocate receipts and enter each return's last legacy date. The initial suggestion places the total in the return containing the date you entered. If £1 of income cannot cover related costs in both returns, the same panel lets you allocate the affected income and costs.

Upload the full-period accounts once. The same file accompanies both returns. If the first CT600 was already filed elsewhere and the second was not, start through Amend filing made elsewhere. In step 1, choose First CT600 already filed, second not yet filed under Filing purpose. We amend the first return and file the second as new.

3. Upload your accounts

Under Your accounts, upload a PDF, .html or .xhtml file of up to 15 MB. Our service requires iXBRL when total income across the accounts period exceeds £6.5 million. This full-period requirement is our service policy. The charity PDF concession considers income together with wholly owned subsidiaries, so use iXBRL if that combined amount exceeds the limit.

We keep and send the file you upload. We do not prepare charity accounts or check uploaded iXBRL with Arelle. You are responsible for the accounts and their tagging. Review the filename and download the attached file before approving.

4. Review, preview and submit

Review the exemption claim, figures and accounts file, then preview the CT600 with its CT600E pages. Supply the signatory and HMRC credentials to submit. There is no tax computation on this route. An explanation PDF accompanies each return. For a long period, preview both CT600 and CT600E sets.

An acknowledgement means HMRC has received the message for processing. Check the final acceptance or rejection. If HMRC rejects the accounts, correct them in the software that prepared them, return to step 2, replace the file and review and submit again if neither return has been accepted. Replacing a file requires fresh approval. If either return has been accepted, changes use an amendment of the filing. We do not currently offer automatic recovery or a retry of only the rejected return in a partly accepted pair. Check both receipts before taking action. Do not submit again while either outcome is pending or unknown.

Companies House and charity regulator filings remain separate. See where charity accounts must go. Read the exemption conditions or the CASC rules before choosing your filing scope. This is general guidance, not a determination that your organisation qualifies.