When can my company file dormant accounts?

A company is dormant (for Companies House purposes) when it has had no significant accounting transactions in the financial year — the key word is transactions, not the bank balance. Money just sitting in the business bank account doesn't break dormancy at all.

That said, the only transactions Companies House ignores are: filing fees paid to Companies House, late-filing penalties, and money paid for shares when the company was incorporated. Anything else technically counts as a transaction — including paying bank fees. If the only movement was a few pounds of bank charges, check carefully before claiming dormancy rather than assuming.

You can file dormant accounts using form AA02 online, and they're still due within 9 months of your year end — late-filing penalties apply to dormant companies too, so don't let the deadline slide.

Your other obligations continue as well: you must still file the confirmation statement every 12 months.

On Corporation Tax: yes, you're right. A dormant company must still file a CT600 for each accounting period unless HMRC has agreed the company is dormant for Corporation Tax and stopped sending you returns. Tell HMRC through your business tax account that the company is dormant — that stops the CT600 cycle until you start trading again.