How to Pay Corporation Tax: Payment Reference, Deadlines and Bank Details (2026 Guide)

Filing your CT600 and paying your Corporation Tax are two separate jobs with two separate deadlines. Many directors assume the tax is collected when the return is submitted. It is not. HMRC expects the money to arrive on its own, usually three months before the return is even due, and it must carry the right reference or it may never reach your company's account.

This guide explains exactly when and how a UK limited company pays Corporation Tax in 2026: the payment deadline, how to find and read the 17-character payment reference, HMRC's bank details, how long each payment method takes, quarterly instalments for larger companies, interest, and how to fix the most common mistakes.

For most companies, Corporation Tax is due 9 months and 1 day after the end of the accounting period. The Company Tax Return (CT600) itself is due 12 months after the end of the period. So the payment deadline always comes first.

This applies to companies whose taxable profits are £1.5 million or less. Larger companies pay earlier, in quarterly instalments (covered below).

A payment counts as made on the day it reaches HMRC, not the day you send it. If the deadline falls on a weekend or bank holiday, make sure the money arrives on the last working day before, unless you are paying by Faster Payments, which HMRC receives on weekends and bank holidays too.

For the full picture of filing deadlines and late filing penalties, see our Corporation Tax deadlines and penalties guide.

An accounting period for Corporation Tax can never be longer than 12 months. If your company's accounts cover a longer period, for example your first accounts after incorporation, or after you extended your year end, HMRC splits it into two Corporation Tax periods:

• the first 12 months, and
• the remaining months.

Each period has its own CT600, its own payment deadline (9 months and 1 day after that period ends) and its own payment reference. A common mistake is paying the whole bill against the first period's reference, or waiting until the second deadline to pay both.

Example: accounts run from 1 March 2025 to 31 May 2026 (15 months). The first Corporation Tax period ends 28 February 2026, so its tax is due on 1 December 2026. The second period ends 31 May 2026, so its tax is due on 1 March 2027.

This is the single most important detail when paying. Corporation Tax payments must use the 17-character payment reference for the specific accounting period you are paying, not just your company's 10-digit Unique Taxpayer Reference (UTR).

The reference is built like this:

So a full reference looks like 1234567890A00105A. Because the two digits change for every accounting period, last year's reference is not this year's reference. Reusing an old one sends the money to the wrong period.

Where to find it:

• your company's HMRC online business tax account, under Corporation Tax,
• the payslip HMRC sends, or
• the "notice to deliver a Company Tax Return" letter for that period.

Use the same period-specific reference if you are paying late, paying interest, or paying a penalty for that period.

Most companies pay by bank transfer. Use the account shown on your HMRC notice. If you are not sure, GOV.UK says to use Cumbernauld.

Paying from an overseas account (in sterling):

Bank details occasionally change, so always check the current figures on GOV.UK's "Pay your Corporation Tax bill" page or your HMRC notice before sending a large payment.

Yes, and many companies should. The payment deadline is three months before the filing deadline, so if you file late in the window you must already know your figures and pay on time anyway. Plenty of directors prepare the CT600 early so they know the exact amount before the payment date, then file whenever is convenient.

If you can't finish the return in time, pay a reasonable estimate by the deadline using the correct reference. If you pay too little, interest runs only on the unpaid amount. If you pay too much, HMRC will repay the difference or offset it once the return is processed.

Paying very early does not usually earn interest for a company that is not in quarterly instalments. HMRC's repayment interest generally runs from the normal due date, or the date you paid if that is later.

On the CT600, any Corporation Tax you have already paid for the period is entered so the return shows the amount outstanding or overpaid, and where any repayment should go.

Companies with taxable profits above £1.5 million for the period are "large" and must normally pay Corporation Tax in quarterly instalment payments (QIPs), mostly during the accounting period rather than after it.

Key points:

• The thresholds are shared. They are divided by the number of related 51% group companies plus one, and reduced proportionally for periods shorter than 12 months. A group of four companies has a £375,000 threshold each.
• Dividends count. The test uses "augmented profits", which add certain dividends received from non-group companies to taxable profits.
• First-year exception. A company that was not large in the previous 12 months does not have to pay by instalments, as long as its profits are no more than £10 million.
• The interest rules are different. Interest on late or underpaid instalments, and on early payments, uses special rates.

If your company is near the limit, also check how associated companies affect your small profits rate and marginal relief limits. That is a separate test from the instalment threshold.

There is no fixed penalty for paying Corporation Tax late. Instead, HMRC charges late payment interest from the day after the due date until the day it is paid. The rate is set at the Bank of England base rate plus 4% and changes whenever the base rate changes. HMRC publishes the current figure on its interest rates page.

Two points are often missed:

• Late payment interest paid by a company is normally deductible for Corporation Tax, and repayment interest received is taxable, under the loan relationship rules.
• Filing late is a separate problem. A late CT600 brings fixed and then tax-geared penalties on top of any interest. Paying on time does not protect you from late filing penalties.

If your company cannot pay in full, contact HMRC before the deadline to ask for a Time to Pay arrangement. HMRC is generally more flexible with companies that make contact early than with those that ignore reminders.

If your company is a close company and a director or shareholder still owes it money at the end of the period, there may be a section 455 charge on the loan. This is reported on the CT600A supplementary page and added to the company's Corporation Tax bill for the period.

It is due on the same date (9 months and 1 day after the period ends) and paid with the same payment reference as the rest of your Corporation Tax. If the loan is repaid within those 9 months, the charge generally falls away. If it is repaid later, the tax is still payable and is reclaimed afterwards.

• Using the UTR alone or last year's reference. Contact HMRC's Corporation Tax helpline with the payment date, amount and the reference you used, and ask for it to be moved to the right period.
• Paying one bill for a long period of account. Split it between the two Corporation Tax periods, each with its own reference and deadline.
• Paying from a personal account without a clear reference. The payment is allowed, but it is easy for it to be misallocated, and it may create a director's loan account entry in your books. Record it properly.
• Assuming a loss means nothing to do. You may have no tax to pay, but you still have to file the CT600. A loss can also be carried back to recover tax already paid for the previous year.
• Paying on the last day by Bacs. Bacs takes 3 working days. Use Faster Payments or CHAPS close to the deadline.
• Overpaying. Claim the repayment on your CT600 and give the bank details for the company's account, or ask HMRC to set the overpayment against another liability.

The hardest part of paying Corporation Tax is not the bank transfer. It is knowing the correct figure: adding back disallowable expenses, claiming capital allowances, using losses, and applying the 19% small profits rate, the 25% main rate or marginal relief in between.

WeFile does this for you. Enter your profit and loss account and balance sheet (or import them from Xero, QuickBooks or FreeAgent), and WeFile works out your Corporation Tax automatically, splits long periods, includes any s455 charge, and shows the amount payable before you file. You can then file the CT600 with HMRC and your accounts with Companies House from the same filing. WeFile does not collect tax: you pay HMRC directly using the reference and bank details above.

For a quick estimate first, try our free Corporation Tax calculator. If you are new to company tax returns, start with What is a CT600 return?

Can I pay Corporation Tax before my accounting period ends?
Yes, though most small companies wait until the period has ended and their figures are final. Companies in quarterly instalments pay during the period by law.

Does HMRC send a bill for Corporation Tax?
Not in the way it does for Self Assessment. The company works out its own liability on the CT600, and it is responsible for paying on time whether or not a reminder arrives.

Do dormant companies pay Corporation Tax?
No. A genuinely dormant company has no taxable profits, so there is nothing to pay. It may still need to file if HMRC sends a notice to deliver a return. See our dormant company accounts guide.

How do I check that HMRC has received my payment?
Sign in to your company's HMRC online account. Payments usually show within a few working days, allocated to the accounting period that matches the reference you used.

Can a director pay Corporation Tax with a personal credit card?
No. HMRC does not accept personal credit cards. Use a business debit card, a corporate credit card (a fee applies) or a bank transfer.