- You must pay your Corporation Tax bill within 9 months and 1 day after your accounting period ends.
- Every accounting period requires a unique 17-character payment reference to ensure HMRC allocates your funds correctly.
- Your Company Tax Return (CT600) is due within 12 months of your year-end, even if your company made a loss or is inactive.
Knowing how to pay Corporation Tax is essential for staying compliant and avoiding penalties while running a UK limited company. Whether you are filing for the first time or managing a growing business, understanding the key deadlines and payment reference numbers is the first step toward a stress-free tax season. Using professional accounting services can help ensure your records are accurate and your submissions are on time.
For the 2026/27 financial year, the main rate of Corporation Tax remains capped at 25% for companies with profits over £250,000, while the small profits rate is 19% for those with profits under £50,000. Staying on top of these figures, along with your specific accounting periods, ensures you allocate the correct funds for your bill.
In this guide for new and small businesses, you’ll learn how to:
- Track your Corporation Tax and filing deadlines.
- Submit your CT600 Company Tax Return online.
- Locate your 17-character payment reference for each period.
- Handle penalties if you miss an HMRC deadline.
When is your Corporation Tax due?
The first step in understanding how to pay Corporation Tax is knowing exactly when your payment is due. Unlike most other business taxes where the filing and payment dates are the same, Corporation Tax features two distinct deadlines:
- The Payment Deadline: You must pay your Corporation Tax within nine months and one day after your accounting period ends. For example, if your financial year ends on 31 March 2026, your payment must reach HMRC by 1 January 2027.
- The Filing Deadline: Your Company Tax Return (CT600) is due within 12 months of your accounting period end.
If it is your company’s first year, your first accounts may cover more than 12 months, creating two separate accounting periods. HMRC requires a separate return and payment for each, though your dates will typically align from the second year onwards.
Setting up a dedicated "Tax Pot" savings account is one of the most effective habits for limited company directors. As you invoice clients throughout the month, transfer 19% to 25% of your estimated profit into this account immediately. By the time your 9-month-and-1-day deadline arrives, you aren't scrambling for funds; you are simply moving money that was already "spent" in your mind.
Finding your Corporation Tax reference number (UTR)
You’ll need your 10-digit Unique Taxpayer Reference (UTR) whenever you file, pay, or contact HMRC. This is issued automatically when you first register for Corporation Tax.
You can locate your UTR:
- On the “Welcome to Corporation Tax” letter sent by HMRC to your registered office.
- Inside your HMRC online account under the Corporation Tax summary.
- On any previous CT600 submissions or official payment reminders.
If you have misplaced your number, use the official HMRC UTR lookup tool to request it.
Creating Your 17-Character Payment Reference
To ensure your payment is credited to the correct year, you must use a unique 17-character reference for each specific accounting period. The structure is as follows:
- Digits 1–10: Your 10-digit UTR.
- Characters 11–14: Always A001.
- Digits 15–16: The code for your accounting period (e.g., 01, 02).
- Character 17: Always A.
Methods for paying your Corporation Tax bill
HMRC does not accept payments by post; you must pay electronically. When paying, ensure you use the correct bank details for HMRC Cumbernauld (Sort Code: 08-32-10, Account: 12001039) or HMRC Shipley as stated on your notice.
Payment Method | Timeframe | Best For |
Faster Payments | Same or next day | Last-minute, secure transfers |
CHAPS | Same working day | Large, high-value payments |
Bacs | 3 working days | Standard scheduled transfers |
Direct Debit | 3–5 working days | Automating future payments |
You can also pay your Corporation Tax bill online using a debit or corporate credit card via the official Government Gateway portal.
Filing Checklist: Your Company Corporation Tax return (CT600)
Filing your Company Tax Return is the formal process of telling HMRC your business profits and final tax calculation. Every active limited company must submit a CT600 for each period, even if you made a loss.
Before you start, ensure you have:
- Company Accounts: A finalised balance sheet and profit and loss statement.
- Tax Computations: Clear records showing how you adjusted your accounting profit to reach your taxable profit.
- Electronic Format: Most companies must file using iXBRL compatible software.
If you are unsure whether your business is considered “active” by HMRC standards, refer to our guide on trading vs non-trading for Corporation Tax.
Handling late Corporation Tax penalties
Missing your deadline triggers automatic penalties from HMRC. Note that from 1 April 2026, HMRC is increasing several fixed penalties to encourage better compliance.
- 1 day late: £100 fine (rising to £200 from April 2026).
- 3 months late: An additional £100 fine (rising to £200 from April 2026).
- 6 months late: HMRC estimates your tax bill and adds a 10% penalty to that amount.
- 12 months late: Another 10% penalty is added to the estimated bill.
If you cannot pay on time, contact HMRC immediately to discuss a Time to Pay arrangement. For a full breakdown of the consequences of missing deadlines, see our guide on HMRC and Companies House fines.
What to do if there is no Corporation Tax due
If your company has made a loss or has no taxable profits for an accounting period, you must still notify HMRC. Failing to do so will result in automated payment reminders and potential investigation.
You can tell HMRC there is nothing to pay by completing the official Nil To Pay form online. Remember: submitting this form does not remove your legal obligation to file a CT600 Company Tax Return for that period.
How to pay less Corporation Tax
Strategic tax planning ensures you only pay what is legally required and nothing more. You can pay less Corporation Tax by claiming all qualifying business expenses, making employer pension contributions, and utilising available tax reliefs.
How Sleek helps you stay ahead of the Corporation Tax deadline
Managing your Corporation Tax obligations doesn’t have to be a source of stress. Between tracking accounting periods, calculating complex tax reliefs, and ensuring your 17-character payment reference is perfect, the admin can quickly become overwhelming.
Sleek supports limited companies with expert accounting services, from initial registration to the final submission of your CT600. Our team ensures your records are accurate, your filings are on time, and your business remains fully compliant with HMRC, allowing you to focus on growth rather than paperwork.
Disclaimer: The preceding information is not legal advice. This content is aimed to provide general guidance. For more formal or legal advice, contact Sleek directly.
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FAQs on how to pay Corporation Tax
How do I pay my Corporation Tax bill online?
The most common way is via online bank transfer (Faster Payments) or the Government Gateway using a debit card. Always include your 17-character payment reference to ensure the funds are allocated correctly.
What is the Corporation Tax rate for 2026?
For the 2026/27 financial year, the Main Rate is 25% for profits over £250,000. A Small Profits Rate of 19% applies to profits of £50,000 or less, with marginal relief available for those in between.
How do I find my Corporation Tax payment reference?
Your unique 17-character reference is found on your HMRC ‘notice to deliver a tax return’ or in your online business tax account. It changes every year, so do not reuse a reference from a previous accounting period.
How long does it take for HMRC to receive a Corporation Tax payment?
Faster Payments and CHAPS usually reach HMRC on the same or next day. Bacs and Direct Debit typically take 3 to 5 working days. You can check your HMRC account after a few days to verify the status.
Can I pay Corporation Tax by credit card?
HMRC accepts corporate credit cards, but there is a non-refundable fee for this service. Personal credit cards are not accepted, though you can use a personal debit card without incurring a fee.
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What is a “Nil Return” for Corporation Tax?
A nil return is submitted when your company has no tax to pay (for example, due to making a loss). You must still file a CT600 and use the ‘nil to pay’ form to stop HMRC from sending payment reminders.
What are the late payment penalties for Corporation Tax in 2026?
From 1 April 2026, fixed penalties for late filings start at £200 for being one day late and rise to £400 if you are more than three months late. In addition to these fixed fines, HMRC charges daily interest on any unpaid tax.
