When Must a UK Limited Company File Accounts at Companies House?

The accounting reference date and how it is set

Every company has an accounting reference date (ARD), which marks the end of its financial year. When a company is incorporated, the ARD is automatically set to the last day of the month in which the first anniversary of incorporation falls — so a company incorporated on 14 March would have an ARD of 31 March. Directors can change the ARD, within certain restrictions, by filing a form AA01 at Companies House. The date of the ARD determines when accounts must be filed.

Deadline for first accounts versus subsequent accounts

For a company's first set of accounts, the filing deadline is 21 months from the date of incorporation or 3 months from the ARD, whichever is longer. This gives newly incorporated companies more time to get their affairs in order. For all subsequent accounting periods, private limited companies must file within 9 months of the ARD, and public limited companies within 6 months. Dormant companies are not exempt from these requirements — they must still file, typically using the abbreviated dormant accounts procedure.

Companies House does not automatically grant extensions. In exceptional circumstances — such as a natural disaster or administration — an extension may be available on application, but the bar is high and must be applied for before the deadline passes.

Late-filing penalties and their escalation

Penalties are levied automatically when accounts arrive after the deadline. For private companies, the penalty is £150 for accounts up to one month late, rising to £375 for one to three months, £750 for three to six months, and £1,500 for accounts more than six months late. For public companies the penalties are higher. Importantly, if the company was also late in the previous year, the penalty is doubled. There is no discretion for Companies House to waive the penalty on grounds of ignorance or administrative error.

Beyond the financial penalty, persistent late filing damages the company's credit profile and is visible on the public register — lenders and trade counterparties routinely check filing history when assessing a business.

What is actually filed at Companies House

The accounts filed at Companies House are not necessarily the full statutory accounts prepared for tax purposes. Small companies (those meeting at least two of: turnover below £10.2m, balance sheet total below £5.1m, fewer than 50 employees) may file abridged accounts, which omit the profit and loss account, meaning turnover and profitability are not publicly visible. Micro-entities have even more limited disclosure requirements. However, HMRC receives the full statutory accounts alongside the Corporation Tax return. Confirm the appropriate filing level with your accountant, as the thresholds and options can change.