The Fundamental Rule
For most private limited companies, your annual accounts must be filed with Companies House within 9 months of the end of your financial year. This means if your financial year ends 31 December 2025, your accounts are due at Companies House by 30 September 2026. The 30 September 2026 is your filing deadline.
It’s also worth knowing that your annual accounts count as filed on the date Companies House actually accept them, not the date you send them. This is something that catches a lot of directors out, so it's worth not leaving it to the last day.
Filing your First Set of Annual Accounts? The Rule is Different
If your company has been recently incorporated and you are filing your first set of accounts, your filing deadline is different. Your first annual accounts are due 21 months from the date of incorporation, rather than 9 months from the end of your financial year.
For example, if your company was incorporated on 2nd January 2025, your first accounts are due by 2nd October 2026.
What is an Accounting Reference Date?
Your accounting reference date, or ARD, is the last day of your company’s financial year. Typically, this is set by Companies House automatically as the last day of the month of company incorporation. So, if your company was incorporated on 16 March 2026, your ARD will be 31 March every year.
If you wish to do so, you can change your ARD by completing form AA01 on the Companies House website, yet it is worth noting that there are rules around how often you can do this and how much you can extend it by.
Two Separate Deadlines? Companies House vs HMRC
It is common for directors to mix these up. They are two completely separate obligations with different deadlines:
- Annual Accounts to Companies House: 9 months after your financial year end, as mentioned above.
- CT600 Corporation Tax Return to HMRC: 12 months after your accounting period end.
- Corporation Tax payment: 9 months and 1 day after your accounting period end.
So, what does this all mean? Well, this means that your Companies House accounts are actually due before your CT600, and your tax payment falls in between the two. Therefore, it is worth noting all three dates in a secure place to avoid any potential confusion.
It is definitely also worth noting that since 31 March 2026 the joint HMRC and Companies House free filing service has permanently closed. This means accounts and CT600s need to be filed through compatible software, such as the packages we provide here at Easy Digital Filing.
What Will Happen if I File Late?
Companies House applies automatic late filing penalties for missed filing deadlines. The longer you leave it, the higher the potential penalty.
- Up to 1 month late: £150
- 1 to 3 months late: £375
- 3 to 6 months late: £750
- More than 6 months late: £1,500
These penalties are also doubled if you file late two years in a row, in addition to Companies House retaining the power to strike your company off the register for consistent non-compliance. So, it is advisable to file earlier rather than later.
How Can I Check My Deadline?
You can check your exact filing deadline at any time by simply searching for your company on the Companies House Website. Your accounts due date will be shown within your company’s public profile.
Can I Get an Extension
An extension is only granted in certain circumstances and must be applied for before your deadline has passed. You cannot apply retrospectively once your deadline has passed, so if you have missed your deadline, you may be required to make other arrangements.
Valid circumstantial reasons include unexpected illness, natural disasters or exceptional circumstances outside of your control. Simply not being organised or having an accountant who is too busy does not qualify as a valid reason.
Overall
The 9-month deadline comes around a lot quicker than many directors anticipate, particularly in their first year of trading when they usually have a lot on their plate. Getting your accounts prepared early gives you time to review everything carefully and avoid any last-minute issues. Easy Digital Company makes it straightforward to incorporate your company and manage your ongoing compliance from day one.
For most private limited companies, your annual accounts must be filed with Companies House within 9 months of the end of your financial year. This means if your financial year ends 31 December 2025, your accounts are due at Companies House by 30 September 2026.
- Annual Accounts to Companies House: 9 months after your financial year end, as mentioned above.
- CT600 Corporation Tax Return to HMRC: 12 months after your accounting period end.
- Corporation Tax payment: 9 months and 1 day after your accounting period end.
- Up to 1 month late: £150
- 1 to 3 months late: £375
- 3 to 6 months late: £750
- More than 6 months late: £1,500



















