Paying your Corporation Tax after you file

Last updated: 12 October 2026

Short version. Filing your CT600 does not pay the tax. You pay HMRC directly, by each return's payment deadline, using the 17-character payment reference for that return's accounting period. The Corporation Tax is usually due 9 months and 1 day after the end of the accounting period, which is earlier than the CT600 filing deadline. You do not have to wait for the amount to appear in your HMRC online account before you pay. For an accounts period longer than 12 months there are two returns, so there are two payments, two deadlines and two payment references.

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On this page

After HMRC accepts your CT600One payment per returnAccounts periods over 12 monthsWhere you see it: Review & file, then your filing page

What this guide covers

Filing your CT600 does not pay the tax. You pay HMRC directly, by each return's payment deadline, using the 17-character payment reference for that return's accounting period.

The Review & file page shows the tax and each payment deadline before you submit. Your filing page shows the tax calculated for the filing after you submit.
SimpleCompanyTax does not collect, hold or pass on your Corporation Tax. Entering an amount already paid in the wizard does not send money to HMRC either. Tax you paid before filing
Each Corporation Tax accounting period has its own 17-character payment reference, which changes every period. HMRC: payment reference
When your accounts period ends more than 12 months after it starts, even by one day, each of the two returns is a separate accounting period with its own deadline and reference. Deadlines for two returns
Companies House does not collect Corporation Tax. Its accounts deadline is separate and is shown on the same Review & file card.

Is this the right guide for you?

Use it if all of these are true

You are filing, or have filed, a CT600 that shows Corporation Tax to pay.
Your company is not required to pay Corporation Tax by quarterly instalments, so its tax is due 9 months and 1 day after the end of its accounting period.
You want to know which amount to pay, by when and with which reference.

Do not use it if

You already paid some or all of the tax before filing and want the CT600 to show it.Use instead: Filing a CT600 when tax is already paid
Your company must pay by quarterly instalments. HMRC decides this from its profits, its associated companies and the length of the accounting period, and some companies above the threshold are exempt.Use instead: HMRC: who pays by instalments
There is no Corporation Tax to pay for the period.Use instead: HMRC: tell HMRC no payment is due

Common mistake: the wrong payment reference

The amount is usually right. The reference is what goes wrong. Two versions come up most often: reusing last year's reference, which your bank may have saved with HMRC as a payee, and paying the tax for both returns of a long period under one reference. HMRC says a payment with the wrong reference may be delayed or used to pay a different tax bill. If that happens, HMRC's Corporation Tax general enquiries team can move the payment.

More help: HMRC: payment reference · HMRC: Corporation Tax general enquiries

Worked example

Company: Spruce Example Ltd
Accounts period: 1 January 2025 to 31 March 2026 (15 months)
First CT600: 1 January 2025 to 31 December 2025. Corporation Tax £6,935
Second CT600: 1 January 2026 to 31 March 2026. Corporation Tax £1,710
Payment deadlines: £6,935 by 1 October 2026, and £1,710 by 1 January 2027
Payment references: One for each return, from HMRC

The company and all figures on this page are fictional.

Before you start

The payment reference for each return: On HMRC's notice to deliver your tax return, on any HMRC reminder, or in your company's HMRC online account under the Corporation Tax statement and accounting periods. Where HMRC shows it
The amount for each return: The Corporation Tax on that return. For two returns, each return’s own CT600 and tax computation show its amount.
The deadline for each return: Shown on the Review & file page before you submit. It is 9 months and 1 day after that return ends.
A way to pay: A bank transfer, Direct Debit, debit card or corporate card. Allow time for the payment to reach HMRC. HMRC: ways to pay

The company and all figures on this page are fictional.

Step by step

Review & file
The Corporation tax due card shows the tax for the whole filing, both returns together for a long period. For Spruce Example Ltd:
Corporation tax due
£8,645 .00
On taxable total profits of £45,500 at 19.0% · small profits
Corporation Tax payment due
The payment deadline for a period of 12 months or less
CT payment due (Return 1)
For a long period, the first return’s deadline. 1 October 2026 in the example
CT payment due (Return 2)
The second return’s deadline. 1 January 2027 in the example
CT600 filing deadline
The date the CT600 is due. This is later than the payment deadline for most companies
Corporation Tax payable by instalments
Shown instead of a date when you said the company pays by instalments. Its HMRC payment guidance link opens HMRC's rules
If you entered tax already paid, the card is headed Corporation Tax liability and a Corporation Tax already paid panel shows Tax outstanding for each return.
More help: Tax you paid before filing
After you submit
The filing page lists each return under Gateway submissions. Each shows Accepted once HMRC confirms it. HMRC usually replies within a few minutes, but it can take longer.
Tax calculation
The Corporation Tax calculated for the filing. View breakdown → opens the computation
What we filed with HMRC
The key CT600 figures sent to HMRC, including Corporation Tax payable
Your filing record
The documents for each return. For two returns, HMRC CT600 Submission (Return 1).pdf and Tax Computation (Return 1).pdf show the first return's tax, and the Return 2 files show the second
More help: Filing statuses explained
Pay HMRC
Payment happens outside the filing wizard, on HMRC’s payment service or through your bank. Repeat these steps for each return.
Payment reference
The 17-character reference for that return’s accounting periodDo not reuse an earlier period's reference saved in your bank. Why it changes
Amount
The Corporation Tax for that returnFor a long period, pay each return’s amount under its own reference.
Pay by
That return’s payment deadlineIt is the date the money reaches HMRC that counts.
Keep
Your payment confirmationHMRC’s online account usually updates within a few days of receiving the payment.
More help: HMRC: pay your Corporation Tax bill

Sample outcome

£6,935First return, paid by 1 October 2026 with the reference for 1 January 2025 to 31 December 2025

£1,710Second return, paid by 1 January 2027 with the reference for 1 January 2026 to 31 March 2026

Two payments£8,645 in total, never paid as one amount under one reference

1. When your Corporation Tax shows in your HMRC account

When you file a CT600, you tell HMRC how much Corporation Tax your company owes. You work it out, not HMRC. This is called self-assessment. After HMRC accepts the return, the figure is posted to your company’s HMRC online account.

In practice the amount usually appears within a few working days of acceptance, and occasionally takes longer at busy times. HMRC does not publish a guaranteed timescale for this. Your filing page already shows the tax figure and HMRC's acceptance, so you do not need to wait for the online account to pay.

2. Can I pay before it shows in the account?

Yes. Because Corporation Tax is self-assessed, you do not need to wait for the figure to appear online before paying. Use the correct payment reference for the accounting period (see below), and HMRC matches your payment to that period.

This matters because the deadline to pay is earlier than the deadline to file (section 6), so many companies pay before they file or at the same time, rather than waiting for the online account to update.

3. How to pay HMRC

Find the payment reference for the correct Corporation Tax period in your HMRC online account or on HMRC's notice.
Choose a payment method on HMRC’s payment page and use that period’s reference.
Keep the payment confirmation and check the balance with HMRC. For two returns, check each period.

If you paid before submitting the CT600, follow the tax-already-paid entry steps. Entering a payment figure in the wizard does not send money to HMRC.

You pay HMRC directly. SimpleCompanyTax files your return but does not collect or pass on the Corporation Tax itself. The official options are on GOV.UK’s “Pay your Corporation Tax bill” page. HMRC lists these timings:

Same day or next day: approving a payment through your online bank account, Faster Payments or CHAPS by online or telephone banking, a debit or corporate credit card online, or paying at your bank or building society.
3 working days: Bacs, or a Direct Debit you have set up for HMRC before.
5 working days: a Direct Debit you have not set up for HMRC before.

A corporate credit or debit card carries a fee that is not refunded. A personal debit card has no fee, and you cannot pay with a personal credit card. You cannot pay Corporation Tax by post.

Allow enough time for the payment to clear by the deadline, because it is the date the money reaches HMRC that counts. If the deadline falls on a weekend or bank holiday, the payment must reach HMRC on the last working day before it, unless you pay by Faster Payments. If no tax is due, for example for a loss-making or dormant period, tell HMRC with its “nil to pay” form rather than making a payment.

4. Your payment reference, and why it changes each period

Every Corporation Tax payment needs the 17-character payment reference for the accounting period you are paying. HMRC says the reference changes with each accounting period, so you use a different one each time you pay. Your company's 10-digit Unique Taxpayer Reference (UTR) stays the same, but the payment reference does not.

Do not reuse last year’s reference. If you saved HMRC as a payee in your bank, the bank keeps the reference you used last time, so update it before paying. HMRC says a payment with the wrong reference may be delayed or used to pay a different tax bill.

You will find the correct reference on your notice to deliver your tax return, on any reminder from HMRC, and in your HMRC online account: choose ‘view Corporation Tax statement’, then ‘accounting periods’, then the correct period. HMRC: your payment reference

5. Do I need to choose the accounting period before paying?

Effectively, yes, and you do it through the reference. There is no separate “which year?” question. The 17-character reference is how HMRC knows which accounting period your money belongs to. Pick the reference for the period you are paying. In the online account you select the period, which gives you its reference.

The most common mistake is paying the right amount with the wrong period’s reference. Get the reference right and the payment lands against that period.

6. Payment deadline and filing deadline

These are two different dates, and the payment one usually comes first:

Pay your Corporation Tax: by 9 months and 1 day after the end of the accounting period, unless your company must pay by quarterly instalments. The £1.5 million threshold for instalments is divided between associated companies and reduced for an accounting period shorter than 12 months (Instalment Payments Regulations, regulation 3), and HMRC lists exceptions. Read HMRC's full conditions before relying on the 9-month date.
File your CT600: usually by 12 months after the end of the accounts period. A later HMRC notice can give a later date.

So for most companies the tax is due to be paid before the return is due to be filed. The Review & file page shows both dates for your filing.

More help: Deadlines for two returns

Long accounting periods: two payments

A Corporation Tax accounting period cannot be longer than 12 months. When your accounts cover a longer period, the filing has two CT600s, and each covers its own accounting period. Each one has its own payment deadline, 9 months and 1 day after that return ends, and its own payment reference. The Review & file page lists them as CT payment due (Return 1) and CT payment due (Return 2).

In the example above, Spruce Example Ltd pays £6,935 by 1 October 2026 and £1,710 by 1 January 2027. The first deadline comes three months before the second, so paying both amounts together on the later date would make the first payment late.

More help: GOV.UK: Corporation Tax accounting periods · How a long period is split

7. What most companies do

A typical approach for a small company is:

File first to confirm the exact figure. Your filing page shows the tax calculated for the filing.
Pay HMRC directly soon after, often by Faster Payments bank transfer, using that period’s 17-character reference.
Do not wait for the amount to appear in the HMRC account. Pay by the payment deadline and let the online balance catch up.

This is general guidance for a UK micro-entity, not advice about your specific company. For the current methods, processing times and your exact figures, use GOV.UK’s “Pay your Corporation Tax bill” and your HMRC online account.

Not the right guide?

Open the guide that matches your situation.

Tax already paid before filingShow a payment you made before the CT600 on the return.Accounts period longer than 12 monthsWhy there are two returns and two sets of deadlines.Standard returnFile every CT600 for your accounts period as new returns.

Looking for a different field or step? See all filing wizard guides →

Official sources

Whether this route matches your filings is for you to decide, yourself or with your accountant.

Example companies and figures are fictional. Field names match the filing wizard as of 12 October 2026.