If you receive a ‘Notice to Deliver a Company Tax Return’ from HMRC, your business must file a Company Tax Return, even if it has made a loss or owes no Corporation Tax. Sole traders and partnerships are exempt but must submit a Self Assessment tax return instead. 

 What a Company Tax Return Involves

Filing a Company Tax Return includes:

- Calculating your profit or loss for Corporation Tax, which differs from your annual accounts. 

- Determining your Corporation Tax bill. 

You can file the return yourself or use an accountant. If you operate a limited company, you may also be able to file accounts with Companies House simultaneously. 

Deadlines & Penalties

- Filing Deadline: 12 months after the end of your accounting period. Late submissions result in penalties. 

- Tax Payment Deadline: Usually 9 months and 1 day after the accounting period ends. 

Understanding Your Accounting Period

Your accounting period for Corporation Tax typically aligns with your company’s financial year but cannot exceed 12 months. If your business setup changes, your accounting period may differ.

First Accounting Period: After registering for Corporation Tax, HMRC will provide your accounting period dates. If incorrect, notify HMRC. 

Accounting Period & Financial Year Differences

If your accounts exceed 12 months, you must file two tax returns. For example, if your year-end changes from 31 Dec 2023 to 31 Mar 2024, update HMRC before 31 Dec 2024 and file all returns by 31 Mar 2025. 

Stay compliant by checking your business tax account regularly and meeting all tax deadlines.