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HMRC Corporation Tax Online Account: How to Set Up and Use It
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HMRC Corporation Tax Online Account: How to Set Up and Use It

HMRCcorporation taxonline accountGovernment Gateway

HMRC Corporation Tax Online Account: How to Set Up and Use It

Every UK limited company needs an HMRC Corporation Tax online account to file returns and pay tax. This guide walks you through setting up and using your account.

What Is the HMRC Corporation Tax Online Account?

Your company's Corporation Tax online account lets you:

  • View your corporation tax liabilities and payments
  • Check filing deadlines
  • See your Unique Taxpayer Reference (UTR)
  • View previous CT600 returns
  • File your CT600 (previously via HMRC's free tool — ending March 2026)

It's accessed through the Government Gateway, HMRC's authentication system.

Step 1: Register Your Company for Corporation Tax

If you've just incorporated, you need to register for Corporation Tax within 3 months of starting to trade.

How to Register

  1. Go to gov.uk/limited-company-formation/set-up-your-company-for-corporation-tax
  2. You'll need:
    • Company Registration Number (CRN)
    • Date of incorporation
    • Date you started trading
    • Company's registered address
    • Nature of business (SIC code)
    • Accounting period end date
  3. Submit the registration

HMRC will send your Unique Taxpayer Reference (UTR) by post within 2-4 weeks. Keep this safe — you need it for every tax filing.

Step 2: Create a Government Gateway Account

If you don't already have a Government Gateway account for your company:

  1. Go to gov.uk/log-in-register-hmrc-online-services
  2. Click "Create sign in details"
  3. Choose "Organisation" (not Individual)
  4. Enter your email address
  5. Create a password
  6. Note down your Government Gateway User ID — you can't recover it easily

Step 3: Enrol for Corporation Tax

Once you have your UTR and Government Gateway account:

  1. Log in to your Government Gateway account
  2. Click "Add a tax" or "Enrol for a service"
  3. Select "Corporation Tax"
  4. Enter your UTR
  5. HMRC will send an activation code by post (7-10 working days)
  6. Log back in and enter the activation code

After activation, you can view your Corporation Tax account online.

Step 4: Using Your Account

View Your Tax Position

Your account shows:

  • Amount owed — any outstanding corporation tax
  • Payment history — previous payments
  • Filing history — submitted CT600 returns
  • Deadlines — when your next return and payment are due

Make a Payment

You can pay corporation tax via:

  • Direct Debit — set up through your online account
  • Bank transfer — using your payment reference
  • Corporate credit card — via HMRC's online payment service
  • At your bank — with a paying-in slip

How to pay corporation tax →

Your payment reference is your UTR followed by the letter A and the period end date (e.g., 1234567890A25031 for period ending 31 March 2025).

Payment reference guide →

Filing Your CT600 Return

Option 1: HMRC's Free Filing Tool (Ending March 2026)

HMRC has provided a free online CT600 filing tool for years. However, this is being retired in March 2026. After that date, you'll need to use commercial software.

Option 2: Commercial Software (Recommended)

Third-party tools like Taxpipe let you:

  • File your CT600 directly with HMRC
  • Generate iXBRL accounts automatically
  • Calculate corporation tax, marginal relief, and FY splitting
  • Get instant confirmation from HMRC

File your CT600 for £59 with Taxpipe →

Option 3: Hire an Accountant

An accountant can file on your behalf. Typical costs:

  • Small company CT600: £300-£800 per year
  • Includes annual accounts preparation
  • May include payroll and VAT

For simple companies (single director, straightforward income), self-filing with software like Taxpipe saves £200-£700 per year.

Common Issues

"I've lost my UTR"

Options:

  1. Check old HMRC correspondence
  2. Call HMRC Corporation Tax helpline: 0300 200 3410
  3. Write to: Corporation Tax Services, HM Revenue & Customs, BX9 1AX

"I can't log in to Government Gateway"

  1. If you've forgotten your User ID: you'll need to create a new account
  2. If you've forgotten your password: use the "Forgotten password" link
  3. If your account is locked: wait 2 hours or call HMRC

"My activation code hasn't arrived"

Activation codes take 7-10 working days by post. If it's been longer:

  1. Check the registered office address is correct at Companies House
  2. Request a new code through Government Gateway
  3. Call HMRC if it's been more than 3 weeks

"HMRC shows I owe tax but I've already paid"

Payments can take 3-5 working days to show in your account. If it's been longer:

  1. Check you used the correct payment reference
  2. Check the payment left your bank account
  3. Call HMRC with your payment reference and bank details

Key HMRC Contact Details

ServiceContact
Corporation Tax helpline0300 200 3410
Opening hoursMon-Fri 8am-6pm
Textphone0300 200 3419
PostHM Revenue & Customs, BX9 1AX

Next Steps

  1. Register for Corporation Tax if you haven't already
  2. Set up your Government Gateway account and enrol for CT
  3. File your CT600 with Taxpipe when your return is due — £59, no accountant needed

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