Wondering when your corporation tax due date is? UK companies must pay corporation tax 9 months and 1 day after their accounting period ends. So if your company’s financial year ends on 31 December, you’ll need to pay your corporation tax by 1 October the following year.
You also need to file your Company Tax Return (called a CT600 form), but this has a different deadline. You have 12 months from when your accounting period ends to submit this return.
If you miss either of these deadlines, you’ll face penalty fees and interest charges. That’s why it’s so important for UK business owners to know exactly when their corporation tax is due.
In this guide, we’ll explain everything you need to know about corporation tax, including:
- What is corporation tax?
- When is corporation tax due?
- How do I determine the corporation tax deadline for my company?
- And much more…
Let’s get into it!
See Our Packages
What Is Corporation Tax and Who Needs to Pay It?
Corporation tax is the tax that UK limited companies pay on their profits. Instead of being taxed on what you earn as a person, your business is taxed on its annual profits.
Corporation tax applies to taxable profits, which include trading profits, investments, and chargeable gains. It is your responsibility as a director to inform HMRC that your business owes this tax and ensure the amount is worked out correctly.
If you’re a sole trader or run a partnership, you don’t pay corporation tax. Instead, you pay tax on your business profits through your personal tax return.
When Is Corporation Tax Due?
The deadline to pay your tax is actually earlier than the deadline to file your tax return. For most small and medium-sized companies, you’ve got exactly nine months and one day from the end of your accounting period to get that payment to HMRC.
Example:
- Year ends on 31 March 2026 → Corporation tax payment due on 1 January 2027.
- Year ends on 31 December 2026 → Corporation tax payment due on 1 October 2027.
This might seem odd, but that’s just how the system works. HMRC expects the money before they even receive the final paperwork (the CT600 return).
How to Register for Corporation Tax?
After setting up your limited company, you should first register it with HMRC for corporation tax. You can also register online. Your business should be registered within three months of trading. Trade includes buying, selling, renting a property, advertising and employing someone, etc.
You may be charged with a penalty if you register late for corporation tax. So keep it on the top of your checklist.
What are the Rates of Corporation Tax?
The current corporation tax rate on a company’s profit is 19%. Earlier in 2016-17, it was 20%. This rate depends on the amount of profit you earn as a company. The current government has vowed to keep the corporation tax rate low.
Corporation Tax Rate for Limited Company:
You need to pay the tax rate as per the accounting period of your company. To find the accounting period, visit the government website. This tax is usually in line with the company’s annual accounts and financial statements. Normally the accounting period for most businesses is 12 months.
How to Pay Corporation Tax?
You pay corporation tax after knowing how much you owe and how much is due. There are different payment methods to pay this tax:
- Online or telephone banking takes a day or two
- CHAPS works on the same day or the next
- BACS takes three working days
- The direct debit takes three days
- Online by debit or corporate credit card takes three days
- Bank or building society takes three days
- If you’re doing direct debit for the first time it’ll take five days
How Do I Find Out What Rate of Corporation Tax I Need to Pay?
The corporation tax rate you pay depends on your company’s annual taxable profits. Since April 2023, the UK has had a tiered system:
- A small profit rate (19%) applies if your company’s profits are £50,000 or less.
- Main rate (25%) applies if profits are over £250,000.
- Marginal relief applies if profits fall between £50,001 and £250,000, gradually increasing the effective rate from 19% up to 25%.
To figure out your exact tax rate, start by working out your “augmented profits.” This simply means taking your taxable profit and adding any dividends received from non-group companies.
Important: if you have “associated companies” (other businesses under the same ownership or control), those £50,000 and £250,000 limits get split between all your associated companies. This could bump you into a higher tax rate much faster than you might expect.
What Are the Key Dates and Filing Deadlines for Limited Companies in the UK?
There are three core deadlines that every UK limited company director should keep in one place:
Corporation Tax Payment (9 months and 1 day): This is the deadline to actually pay the money you owe to HMRC. It is calculated from the end of your accounting period.
Statutory Accounts to Companies House (9 months): You must file your full annual accounts with Companies House within nine months of your financial year-end. Note that the deadline is usually one day before the corporation tax due date.
Company Tax Return / CT600 (12 months): You have a full year from the end of your accounting period to tell HMRC exactly how you calculated your tax.
Note: You must also file a Confirmation Statement at least once a year, within 14 days of the end of your review period.
See Our Packages
How Do I Determine the Corporation Tax Deadline for My Company?
The easiest way to find your specific corporation tax due date in the UK is to look at your “accounting period” for corporation tax. Most of the time, this matches your company’s financial year (the period covered by the accounts you send to Companies House).
Here is how to work it out in three simple steps:
- Step 1: Identify your year-end. Look at your previous accounts or check the Companies House register to see when your financial year closes (e.g., 31 March).
- Step 2: Count 9 months forward. From that closing date, jump ahead nine months (e.g., 31 March becomes 31 December).
- Step 3: Add one day. This gives you your final payment deadline (e.g., 1 January).
| If your Accounting Period ends on: | Your Payment Deadline: | Your CT600 Filing Deadline: |
| 31 March 2026 | 1 January 2027 | 31 March 2027 |
| 30 June 2026 | 1 April 2027 | 30 June 2027 |
| 30 September 2026 | 1 July 2027 | 30 September 2027 |
| 31 December 2025 | 1 October 2026 | 31 December 2026 |
How Do I Pay Corporation Tax Liability?
HMRC no longer accepts corporation tax payments at the Post Office. All payments must now be processed electronically.
Here’s how you can pay corporation tax due:
- Online or Telephone Banking (Faster Payments): This is the most efficient method, usually reaching HMRC on the same or next day.
- HMRC App: Download the official HMRC app from the App Store or Google Play. You can pay quickly by selecting ‘pay by bank account’. It will securely open your banking app and pre-fill your payment details and reference number for you.
- Direct Debit: Set this up through your HMRC online account. It takes 5 working days to process the first time you set it up, and 3 working days for future payments.
- Debit Card: You can pay online using the “Pay now” service on the GOV.UK website. (Note: Corporate cards incur a fee, and personal credit cards are not accepted.)
- CHAPS: A same-day payment method often used for larger amounts. However, your bank will typically charge a fee for this service.
- Bacs: A standard transfer that typically takes 3 working days.
To ensure your payment is allocated correctly when your corporation tax is due, you must use the correct 17-character payment reference number that corresponds to your specific accounting period. Without this unique identifier, your payment could end up in the wrong place or cause unnecessary delays.
Where can you locate this important reference number? Well, you’ll find it printed on your ‘Notice to deliver a tax return’, any reminder letters from HMRC, or by logging into your HMRC online account.
Important: Always ensure you use the reference number for the correct year, as using an old one could result in the payment being allocated to the wrong period.
Can I Delay My Corporation Tax Payment?
You cannot officially “delay” corporation tax in the sense of moving the legal due date. But if your business is facing genuine financial hardship when your corporation tax is due, you can defer Corporation Tax payments by arranging a Time to Pay (TTP) arrangement with HMRC.
This allows for instalments, typically over 3 to 6 months. These arrangements can also be extended up to 12 months if you can demonstrate a clear need.
Also, remember that, even if HMRC agrees to a payment plan, delaying the full payment is not free. HMRC charges daily interest on any unpaid tax from the original due date until it is fully cleared. As of March 2026, the current late payment interest rate is 7.75% (the late payment interest rate is set by HMRC and may change periodically).
If you agree to a TTP plan before the deadline and stick to it, you can usually avoid late payment penalties. If your return is due on or after 1 April 2026, you will be charged £200 for being just one day late. If you are more than three months late, the penalty rises to £400.
Do I Need to File My Corporation Tax Return by 31 January?
No, this is a very common point of confusion. The 31 January deadline is for Self Assessment (personal tax) and has nothing to do with a limited company. Your company actually has 12 months from the end of its accounting period to file its return.
Even though you have a full year to file the paperwork, remember that the corporation tax due date for the payment is three months earlier.
That’s why many business owners choose to file their return at the nine-month point when they make their payment. This way, they can tick both boxes at once and don’t have to worry about it for another year.
Why Do I Have Two Filing Dates in My First Year?
When you incorporate a company, Companies House automatically sets your year-end for the end of the month you registered in. For example, if you set up your company on 12 March 2025, your first financial year actually runs until 31 March 2026. That is a total of one year and 19 days.
However, HMRC rules state that a single Company Tax Return (CT600) cannot cover a period longer than 12 months.
To bridge this gap, you must split your tax reporting into two periods:
- Period 1: Covers the first 12 months of trading.
- Period 2: Covers the remaining short period (the extra days or weeks) until your official year-end. (e.g., from 12 March to 31 March).
Because you have two separate accounting periods, you end up with two separate tax returns and two different payment deadlines in that very first year.
From your second year onwards, your accounting periods will typically align with a standard 12-month cycle. Hence, you will only have one filing and payment deadline per year.
Are you looking for professional tech-savvy tax advisors and accountants in the UK to guide you? Contact us now!
The Bottom Line
Corporation tax is due 9 months and 1 day after your year-end date, and you’ll need to file the return within 12 months.
Currently, the tax rates stay the same: 19% if you’re dealing with smaller profits and 25% for bigger ones, plus there’s marginal relief that kicks in between those brackets.
Make sure you stay on top of when your accounting period ends and pay the tax before the deadline to avoid any last-minute panic.
How Accotax Can Help
If you need help with filing corporation tax, year-end accounts, VAT, or any other accounting services, visit Accotax. We offer a range of packages designed to fit your unique needs!
Reach out, get an instant quote and let us help you stay tax compliant!
Disclaimer: All the information provided in this article on “When Is Corporation Tax Due? Guide to Rates and When to Pay” including all the texts and graphics, is general in nature. It does not intend to disregard any of the professional advice.