Check Your Corporation Tax Deadlines

How the Calculator Works

Your filing deadlines differ depending on whether your company is trading, dormant, or newly formed. Enter your incorporation date or Accounting Reference Date (ARD), tell us your company status, and we’ll calculate all your deadlines automatically.

What you’ll see:

1. Confirmation Statement: Due 12 months after incorporation, with a 14-day filing window. Required for all companies, whether trading or dormant.
2. Annual Accounts: Your first accounts get 21 months from incorporation. After that, you have 9 months from your ARD each year. Dormant companies must also file accounts.
3. Corporation Tax: Return due 12 months after your accounting period ends. Payment due earlier at 9 months and 1 day after the period ends. Applies to trading companies.

Special cases we handle automatically:

Your first accounting period runs longer than 12 months? We flag that HMRC requires two separate Corporation Tax returns, one for the first 12 months and another for the remaining period. We show you both deadlines.

HMRC doesn’t know your company is dormant? They may still expect a Corporation Tax return and issue penalties if you don’t file. Make sure to inform them.

Each deadline displays a countdown showing how many days you have left or alerts you if a deadline has passed.

What is the date of incorporation?

Your incorporation date marks when Companies House officially registered your company. You’ll find it printed on your certificate of incorporation.

What is the Accounting Reference Date (ARD)?

Your Accounting Reference Date (ARD) marks the end of your company’s financial year. Companies House automatically sets your first ARD to the last day of the month, one year after incorporation. Incorporated on 12 March? Your ARD becomes 31 March.

What is a dormant company?

Your company counts as dormant when it has no significant financial activity during the financial year. Small transactions like Companies House fees don’t count as trading. Want it officially classified as dormant? You need to inform HMRC.

See also: How a Dormant Company Structure Can Help You Save Money

Do dormant companies still need to file accounts?

Yes. Even dormant companies must file annual accounts with Companies House. HMRC may also ask you to file a Corporation Tax return.

What is the deadline for filing annual accounts?

You get 21 months to file your first accounts, counted from your incorporation date. After that? You have 9 months from your Accounting Reference Date (ARD) each year.

When is the Corporation Tax return due?

File your Company Tax Return within 12 months of your accounting period ending. Pay your Corporation Tax earlier—9 months and 1 day after the period ends.

Why might I need to file two Corporation Tax returns?

Your first accounting period runs longer than 12 months? HMRC requires two separate returns:

• One covering the first 12 months
• One covering the remaining period to your ARD

What is a Confirmation Statement, and when is it due?

Your Confirmation Statement proves the details Companies House holds about your company remain accurate. File it 12 months after incorporation, then annually. You have 14 days from the due date to submit it.