Corporation Tax: How and When to Pay

When is Corporation Tax due?

You must pay your Corporation Tax nine months and one day after the end of your accounting period.

Example:
If your accounting period ends on 30 April 2025, your payment deadline is 1 February 2026.

Filing your Company Tax Return (CT600)

You are responsible for calculating how much Corporation Tax your company owes and reporting it on your Company Tax Return (CT600).

Filing deadline: 12 months after the end of your accounting period
Example: If your period ends on 30 April 2025, the filing deadline is 30 April 2026

Although the filing deadline is later than the payment deadline, most businesses complete their return shortly after year-end to confirm their tax liability early.

How to pay Corporation Tax

You can pay your Corporation Tax directly to HMRC using one of the following methods:

Online or mobile banking
Direct Debit
Debit or credit card
Cash or cheque at a bank or building society

When making a payment, you must use your Corporation Tax payment reference. This is a 17-character number that changes for each accounting period. You can find it on:

Your notice to deliver a tax return
Your company’s HMRC online account

Special rules for large companies

If your company has taxable profits above £1.5 million, different rules and payment deadlines apply.

Penalties for Non-Compliance

Failure to notify HMRC

Even if you don’t receive a notice to file a Company Tax Return, you must still inform HMRC if your company owes Corporation Tax.

Deadline: Within 12 months of the end of your accounting period
Penalty: HMRC may charge penalties for failing to notify

Example scenario:
A company begins trading but does not register for Corporation Tax or submit a return on time.

What to do if this applies to you:

Ensure your company is registered for Corporation Tax
Bring all outstanding returns and payments up to date
Keep clear records of when trading started and how profits were calculated

Late filing penalties

If you submit your Corporation Tax Return late, HMRC will apply the following penalties:

1 day late: £100 automatic fine
3 months late: Additional £100 fine
6 months late: 10% of unpaid tax
12 months late: Additional 10% of unpaid tax

If your return is late three years in a row, the £100 penalties increase to £500 each.

Late payment penalties and interest

If you pay your Corporation Tax late:

HMRC charges daily interest on the outstanding amount
Interest applies from the due date until the bill is fully paid
This is charged in addition to any late filing penalties

As of 9 January 2026, the late payment interest rate is 7.75%.

What if you can’t pay on time?

If you know you won’t be able to pay your Corporation Tax bill by the deadline, contact HMRC as soon as possible. You may be able to arrange a payment plan, which can help reduce additional costs.

To avoid cash flow issues, consider setting aside money regularly in a separate account throughout the year so you’re prepared when your tax bill is due.

Can you use personal funds to pay Corporation Tax?

Yes, you can use personal funds to pay your company’s Corporation Tax. However:

The payment must be recorded correctly in your company accounts
It should be treated as either:
- A loan to the company (via a director’s loan account), or
- A personal contribution

The tax liability still belongs to the company, so the payment should be recorded as the company settling its bill, not as a personal tax payment.

Need help?

Corporation Tax can be complex, especially if you’re unsure about deadlines, calculations, or penalties. If you need support:

Speak to a qualified accountant or tax adviser
Get help with preparing and filing your Company Tax Return
Ensure your business stays compliant and avoids unnecessary penalties

Working with an accountant can also help you plan ahead, manage cash flow, and identify potential tax efficiencies.