CT600A explained: loans to directors and shareholders

If your company lent money to a director or shareholder and the loan was still outstanding at the end of the accounting period, you probably need CT600A with your Company Tax Return. It reports the loan and works out the tax the company owes on it under section 455.

Last checked against GOV.UK on 1 October 2026.

A4O Accounts prepares the CT600 from your books and files it with HMRC. See the CT600 software, or get started free.

Who has to complete CT600A

GOV.UK’s guidance says a close company completes CT600A if it has made loans to participators, or their associates, that remain unpaid, or if tax is due under section 455 of the Corporation Tax Act 2010. It also covers benefits conferred on participators under tax avoidance arrangements, which are taxed under section 464A.

Two definitions do the work here:

• A close company is one under the control of 5 or fewer participators, or of any number of participators who are directors. Most owner-managed companies are close companies.
• A participator is a person with a share or interest in the capital or income of the company, and includes any loan creditor. In practice, that’s usually a shareholder.

The everyday case is an overdrawn director’s loan account: a director who is also a shareholder has taken more out of the company than they’ve put in, and still owes it at the year end.

The tax rates

The rate depends on when the loan was made:

The tax is charged on the amount of the loan. The same rate is used to work out the relief when the loan is repaid.

The 35.75% rate and HMRC’s online service

The rate went up from 33.75% to 35.75% for loans made, or benefits conferred, on or after 6 April 2026. HMRC’s notes on the Corporation Tax online service say the service won’t be updated for the new rate until 6 April 2027, and that affected companies should amend their returns after the update.

So if your return covers loans made on or after 6 April 2026 and you file before the service is updated, expect to amend the return later. Check HMRC’s page, linked in the sources below, for the current position before you file.

How the page is laid out

• Part 1 records the loans made during the period that were still outstanding at the end of it, and works out the tax.
• Part 2 gives relief for amounts repaid, released or written off after the end of the period but within 9 months and 1 day of it.
• Part 3 gives relief for amounts repaid, released or written off later than that, where the relief is now due.

The tax payable ends up in box A80, which is carried to box 480 on the main CT600.

Repaying the loan

If the loan is repaid within 9 months and 1 day of the end of the accounting period, the company still reports it on CT600A, but the relief in Part 2 cancels the tax.

If it’s repaid later, the company pays the tax first. It’s repaid to the company once the relief is due, which is 9 months and 1 day after the end of the accounting period in which the loan was repaid. You must claim within 4 years. If the return for the period of the loan has already gone in, the claim is made on form L2P.

Until the tax is paid or the loan is repaid, HMRC adds interest to the tax.

Repaying and borrowing again

Rules stop a loan being repaid just before the deadline and taken out again. GOV.UK says the company still pays the tax if:

• the loan was more than £5,000, and the borrower took another loan of £5,000 or more up to 30 days before or after repaying it
• the loan was more than £15,000, and the borrower arranged another loan when they repaid it

What it means for the director

CT600A is about the company’s tax. The borrower may have tax of their own: a loan that’s interest-free or cheap can be a benefit in kind, and a loan that’s written off is taxed as income. GOV.UK’s director’s loans guide covers the personal side.

CT600A in software

In A4O Accounts you add a CT600A to the return from its tax computation, enter the loans, and the tax is carried into the CT600. The page goes to HMRC with the rest of the return. See the supplementary pages explained and CT600 software.

More in this series: all the CT600 guides.