What is a CT600A? Director's loans and s455 tax in 2026

In short: A CT600A is the Company Tax Return page where a close company reports loans to shareholders or their associates still owed at the period end. It charges section 455 tax of 33.75%, or 35.75% on loans made from 6 April 2026, unless the loan is repaid within 9 months of the period end (GOV.UK: Director's loans: If you owe your company money; HMRC CTM61505).

Working out the balance comes first: see whether the company owes you, or you owe it. Taxley then works out the section 455 tax and adds the CT600A to your return; take the 30-second check to see whether Taxley fits your company.

What is a CT600A?

A CT600A is HMRC's supplementary page for close company loans to participators, filed with the CT600 when a close company has lent money to a participator, such as a shareholder, or to an associate, and the loan was not repaid within the accounting period. The current form is CT600A (2026) Version 3 (GOV.UK: Close company loans to participators (CT600A)).

The CT600A lists each borrower, works out the tax under section 455 of the Corporation Tax Act 2010, claims relief for amounts repaid, released or written off, and carries the net figure to box 480 of the CT600 (HMRC CT600A guidance). Section 455 tax is charged as if it were Corporation Tax, but it is not a tax on profit: the company reclaims it once the loan is repaid, released or written off.

When do you need to include a CT600A with your return?

You need a CT600A when your close company lent money during the accounting period to a participator or an associate and some of it was still owed at the period end, even if it is repaid within the next 9 months and no tax ends up payable.

GOV.UK tells companies to show the amount owed at the period end on form CT600A in both cases (GOV.UK: Director's loans: If you owe your company money). An overdrawn director's loan account counts, because a debt owed to the company is treated as a loan (CTA 2010 s455(4)). The CT600A is part of the Company Tax Return, so it is due with the return, 12 months after the period end (GOV.UK: Company Tax Returns: Overview). Lending fully repaid before the period end needs no CT600A, unless the bed-and-breakfasting rules treat it as still outstanding. A loan brought forward from an earlier year is not charged again (CTM61505).

Section 456 excludes normal trade credit of up to 6 months, loans by a money-lending business, and loans totalling up to £15,000 to a full-time director or employee without a material interest, broadly more than 5% of the ordinary shares counting associates (s456; s457).

Which companies are close companies?

A close company is one controlled by 5 or fewer participators, or by any number of participators who are directors (CTA 2010 s439). A company whose shares are all held by one or two director-shareholders is therefore close.

A participator is anyone with a share or interest in the company's capital or income, including a shareholder or a loan creditor (s454), and an associate includes a participator's relative or business partner (HMRC CT600A guidance). Sections 442 to 447 list exceptions, and section 455 applies only if the company is close when the loan is made (CTM61505).

What is the section 455 tax rate in 2026?

Section 455 tax is 33.75% on loans made from 6 April 2022 to 5 April 2026, and 35.75% on loans made on or after 6 April 2026. The rate is the dividend upper rate for the tax year in which each loan is made (CTA 2010 s455(2)), which Finance Act 2026 raised to 35.75% for 2026–27 (ITA 2007 s8; CTM61505).

A company with a 30 June 2026 year end therefore pays 33.75% on amounts lent up to 5 April 2026 and 35.75% on amounts lent after that. On 24 September 2026, GOV.UK's director's loans page and HMRC's CT600A completion notes still showed 33.75% as the latest rate, so go by the date of each advance.

Figures checked on 24 September 2026 against HMRC's manual CTM61505 and ITA 2007 s8(2).

When is section 455 tax due, and when is none payable?

Section 455 tax is due 9 months and 1 day after the end of the accounting period in which the loan was made, the same day as the company's Corporation Tax, and box 510 of the CT600 adds it to that bill (CTA 2010 s455(3); CTM61610).

None is payable on any part repaid, released or written off before that date, because section 458 relief is then given immediately: for a 31 March 2026 year end, repayments made by 31 December 2026 count. A repayment on or after the due date still earns relief, but only from 9 months and 1 day after the end of the accounting period in which it is made (s458(5)). Late-paid section 455 tax carries interest until the tax is paid or the loan is repaid, and that interest is never refunded (GOV.UK: Director's loans: If you owe your company money).

A loan can be repaid in cash or by crediting a dividend, salary or bonus to the loan account (HMRC CT600A guidance). For paying the bill, see how to pay Corporation Tax; the deadline calculator gives your own dates.

How do the 30-day and £15,000 bed-and-breakfasting rules work?

Section 464ZA of the Corporation Tax Act 2010 stops a repayment from clearing an old loan when the money is borrowed straight back; it replaced section 464C from 30 October 2024 (Finance Act 2025 s81).

Under the 30-day rule, if repayments of £5,000 or more and new loans of £5,000 or more to the same person or an associate fall within any 30 days, and the new loans are made in a later accounting period than the loan being repaid, the repayment is matched to the new loans, up to their amount. Under the arrangements rule, if the borrower owed £15,000 or more just before repaying and arrangements were already in place for at least £5,000 of new lending, the repayment is matched to that lending, with no time limit (s464ZA; CTM61635). The old loan then stays outstanding.

Neither rule applies to a repayment that is itself taxed as the borrower's income, such as a credited dividend or a bonus credited after PAYE; a dividend paid out in cash and paid back in does not count (CTM61642).

What are the parts of the CT600A form?

The CT600A (2026) Version 3 has company details in boxes A1 to A4, three numbered parts and a summary. Box A80 in the summary feeds the CT600, box 95 on the CT600 marks it enclosed, and HMRC says most companies skip Part 3 (HMRC CT600A guidance). Our guide to how to fill in a director's loan on the CT600A goes through it box by box.

Box numbers checked on 24 September 2026 against CT600A (2026) Version 3. For every other box, see CT600 boxes explained.

Worked example: how much s455 tax is due on an £18,000 director's loan?

A close company with a 31 March 2026 year end owes £4,050.00 of section 455 tax when its sole director-shareholder, who owed nothing on 1 April 2025, drew £18,000 during the year and repaid £6,000 in cash on 15 December 2026 with no re-borrowing. Every advance is charged at 33.75%, and the return, filed after the repayment, claims it in Part 2.

The £4,050.00, which is 33.75% of the £12,000 still owed, is due by 1 January 2027 with the Corporation Tax. If the £12,000 is repaid on 31 March 2027, the last day of the next accounting period, relief is due from 1 January 2028. Repaid one day later, on 1 April 2027, it falls in the period ending 31 March 2028 and relief waits until 1 January 2029 (s458(5)). Relief is at 33.75%, the rate for the tax year the loan was made in, whatever the rate when it is repaid.

Re-borrowing changes the section 455 answer. In the £18,000 example, if the director borrows £6,000 again on 5 January 2027, the repayment and the new loan are each at least £5,000, fall within 30 days, and the new loan is in a later accounting period. The 30-day rule matches the repayment to the new loan, so Part 2 is empty and box A80 is £6,075.00. If the return had already claimed that relief, the company must tell HMRC within 3 months (Finance Act 2025 s81). Had the £6,000 been repaid by crediting a dividend taxed as the director's income, the rule would not apply.

When do you get section 455 tax back after the loan is repaid?

HMRC repays section 455 tax, but not interest, once the loan is repaid, released or written off, and not before 9 months and 1 day after the end of the accounting period in which that happened (GOV.UK: Director's loans: If you owe your company money; CTA 2010 s458).

A repayment within 9 months of the end of the year the loan was made in is relieved in Part 2 of that year's CT600A if the return is filed after the repayment, or by amending the return. For a later repayment, the company claims once relief is due: on the loan year's CT600A, filed or amended online, if the claim is within 2 years of that year's end, and otherwise on form L2P. The claim must be made within 4 years from the end of the financial year of the repayment (s458(3)).

Does the director pay personal tax on an overdrawn loan account?

The director pays Income Tax on a benefit in kind if the loan is interest-free or cheap and the director's loans total more than £10,000 at any time in the tax year (GOV.UK: Director's loans: If you owe your company money; ITEPA 2003 s180). The benefit is interest at HMRC's official rate, 3.75% from 6 April 2026, less any interest paid (HMRC official rates).

£12,000 owed interest-free for the whole of 2026–27 gives a £450 benefit if the rate stays at 3.75% all year. The company reports it on form P11D and pays Class 1A National Insurance on it (GOV.UK: Loans to employees: what to report and pay), and the director reports it through Self Assessment. This charge comes on top of the company's section 455 tax (CTM61505).

Writing off or releasing the loan swaps the company's section 455 cost for a personal tax bill. The company reclaims its section 455 tax on the same timetable as a repayment but gets no Corporation Tax deduction for the amount written off (CTM61655). The director pays Income Tax on it through Self Assessment, and the company deducts Class 1 National Insurance, but not PAYE tax, through payroll and reports it on form P11D (GOV.UK: director's loans; GOV.UK: loans to employees).

How does Taxley handle a CT600A?

Taxley works out section 455 tax on a director's or other participator's loan that is still outstanding, and the relief due when it is repaid, and includes the CT600A in the return it files to HMRC.

Taxley does not support bed-and-breakfasted loans unless every repayment was a credited dividend, salary or bonus, and it doesn't handle loans to trustees, partnerships or companies, loans made through another person or company, or loans by a money-lending company. See pricing, or take the 30-second check to see whether Taxley fits your company.

Frequently asked questions

Do I need a CT600A if the loan was repaid within 9 months?

Yes, if lending made in the period was still owed at the period end. GOV.UK says to show the amount owed on form CT600A. Part 2 then relieves what was repaid before the due date, so box A80 can be nil.

Is the s455 rate 33.75% or 35.75%?

It depends on when each loan was made: 33.75% from 6 April 2022 to 5 April 2026, and 35.75% on or after 6 April 2026. The company's year end does not decide the rate.

Does a director's loan under £10,000 still need a CT600A?

Yes, if the borrower is a participator and the loan was owed at the period end. £10,000 is the personal benefit-in-kind threshold. The only amount-based exception to section 455 is £15,000 for full-time directors or employees without a material interest.

Can a dividend repay a director's loan?

Yes. A dividend, salary or bonus credited to the loan account counts as repayment, and a credited dividend taxed as the director's income is outside the bed-and-breakfasting rules. A dividend paid out in cash and paid back in is not.

General information for UK company directors, not personalised tax advice. Rates, dates and box numbers checked against GOV.UK, HMRC manuals and legislation.gov.uk on 24 September 2026.