Fourteen days is the whole margin
The confirmation statement has the shortest window of anything a company files, and the window moves every time you use it early.
How the clock is set
A company must review its records and file at least one confirmation statement every twelve months. The review period ends twelve months after the confirmation statement date on the last statement, or twelve months after incorporation if this is the first one.
After the review period ends you have fourteen days. That is the entire margin, and it does not stretch for weekends, holidays or the fact that you were verifying your identity.
Filing early is not free
You do not have to wait for the review period to end. But if you file early, a new review period starts from that date, which means next year's deadline moves forward too.
That is fine if you meant to do it. It is a nasty surprise if you filed in March to get it off your desk and then diarised the old date.
What it costs and what happens if you skip it
Fifty pounds to file online, one hundred and ten by post. The fee is paid with the first statement in each twelve month payment period.
Not filing is a different order of problem. You can be fined up to 5,000 pounds and the company may be struck off.
What the form can and cannot change
A confirmation statement can only report changes to the SIC code, the statement of capital, the trading status of shares, an exemption from reporting PSC information, and shareholder information.
Everything else, a new director, a change of registered office, a change of name, goes through its own filing. People lose weeks assuming the annual statement will sweep it all up.
You must also provide a registered email address if you have not already. Companies House uses it to contact you, and it stays off the public register.
The dates for your own company come out of the deadline calculator, and the filing itself is described in the dossier.