Registering for Corporation Tax with HM Revenue & Customs (HMRC) is a crucial step for any limited company operating in the UK. It ensures that your business complies with tax obligations and avoids penalties. This guide will walk you through the timelines, process, and what to expect after registration.
| Aspect | Details |
|---|---|
| Deadline to register for Corporation Tax | Within 3 months of starting to trade or being incorporated |
| How to register | Online via HMRC’s website |
| Unique Taxpayer Reference (UTR) | Sent by HMRC after company incorporation, required for registration |
| Penalties for late registration | Possible fines and interest charges on unpaid Corporation Tax |
Why You Must Register for Corporation Tax
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Use Free Tax Calculator →Every limited company in the UK is liable to pay Corporation Tax on its profits. Registering with HMRC ensures that your company is on their radar and can submit accurate tax returns. Failure to register within the required timeframe can lead to penalties, even if your company has no tax to pay.
HMRC requires that companies register within three months from the date they start doing business or from incorporation if trading begins immediately. This deadline applies regardless of whether you make a profit or not.
How to Register Online with HMRC
Registering for Corporation Tax is done through HMRC’s online service. Before starting, you’ll need your company’s Unique Taxpayer Reference (UTR), which HMRC sends by post to the company’s registered office address shortly after incorporation.
The registration process involves setting up a Government Gateway account if you don’t already have one. This account allows you to manage your company’s tax affairs in one place. You will provide details such as your company’s name, registration number, date of incorporation, and business activities.
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Understanding Your Unique Taxpayer Reference (UTR)
The UTR is a 10-digit number unique to your company’s tax records. It is essential for all Corporation Tax dealings with HMRC. You cannot complete your Corporation Tax registration without it.
HMRC usually sends the UTR within a few days of your company’s incorporation. If you have not received it after two weeks, check the registered office address you provided to Companies House or contact HMRC directly.
How to Find Your UTR if Lost
- Check any official letters from HMRC addressed to your company
- Log into your HMRC online account if you have already registered
- Contact HMRC’s Corporation Tax helpline with your company details
What Happens After You Register for Corporation Tax
Once registered, you will receive confirmation from HMRC. You must then file a Company Tax Return (CT600) each year, reporting your profits and calculating the Corporation Tax due. For the 2026/26 tax year, Corporation Tax rates vary depending on profits, with the main rate currently set at 25% for companies with profits over £250,000.
If your company’s profits are below £50,000, a lower rate of 19% applies. Companies with profits between £50,000 and £250,000 pay a tapered rate. It’s important to keep accurate financial records to complete your tax return correctly. You can find more about Corporation Tax rates on the GOV.UK website.
Penalties and Important Deadlines
Registering late for Corporation Tax can lead to financial penalties and interest on any tax owed. HMRC’s penalties are designed to encourage timely compliance and can escalate if you continue to delay.
In addition to registering within three months, you must also submit your Company Tax Return and pay any Corporation Tax due within nine months and one day after the end of your accounting period.
- Register for Corporation Tax within 3 months of starting business
- File Company Tax Return within 12 months of accounting period end
- Pay Corporation Tax within 9 months and 1 day after accounting period ends
Missing these deadlines can result in penalties ranging from fixed fines to daily charges, so it’s essential to mark these dates in your calendar as soon as you register.
Registering a Company vs Sole Trader: What’s the Difference?
If you’re deciding whether to register for Corporation Tax by setting up a limited company or operating as a sole trader, understanding the tax implications is key. Sole traders pay Income Tax and National Insurance on profits, whereas limited companies pay Corporation Tax.
Limited companies must register with Companies House and HMRC for Corporation Tax. Sole traders simply register as self-employed with HMRC. For a detailed comparison, see our guide on Sole Trader vs Limited Company.
Key Takeaways
- You must register for Corporation Tax with HMRC within 3 months of starting business or incorporation.
- Your company’s Unique Taxpayer Reference (UTR) is essential for registration and is sent by HMRC after incorporation.
- Register online via HMRC’s website using a Government Gateway account.
- Failure to register on time can result in penalties and interest charges.
- Corporation Tax rates for 2026/26 are 25% for profits over £250,000, 19% for profits under £50,000, with a tapered rate in between.
- Keep accurate records and meet filing and payment deadlines to avoid fines.
How do I know when to register for Corporation Tax?
You must register within three months of starting to trade or from your company’s incorporation date, whichever is earlier. This is required even if your company makes no profit.
What if I don’t receive my Unique Taxpayer Reference (UTR)?
If you haven’t received your UTR within two weeks of incorporation, check your registered office address details with Companies House and contact HMRC’s Corporation Tax helpline to request it.
Can I register for Corporation Tax before receiving my UTR?
No, the UTR is required to register for Corporation Tax. You should wait until HMRC sends this number before completing the registration process.
Official Sources
* GOV.UK: Set up a business · * HMRC: Income Tax rates · * HMRC: Corporation Tax · * HMRC: VAT registration