I run a UK limited company on my own, and I build small tools. One of those tools knew my filing deadline, knew exactly what missing it would cost, and never once mentioned the thing that would actually have helped. That omission is worth about £150, so here it is written down plainly.
The part everybody knows
Miss your Companies House accounts deadline and the penalty is automatic. No warning letter first, no discretion. The published scale for a private company:
| How late | Penalty |
|---|---|
| Not more than 1 month | £150 |
| More than 1 month, up to 3 months | £375 |
| More than 3 months, up to 6 months | £750 |
| More than 6 months | £1,500 |
And the one that catches people twice: the penalty doubles if you file late in two successive financial years.
The part almost nobody mentions
You can ask Companies House for more time. It is free, the application takes about fifteen minutes, and you do it on their own service.
But you have to apply before your filing deadline. From the gov.uk guidance, in their words: you must apply for the extension, or file your accounts, before your filing deadline, or you will receive a late filing penalty.
Read that again, because it is the entire point of this post. The window to ask for more time closes on exactly the day the penalty starts. There is no grace period in which you notice you are late and then apply. The moment you are late, the option you had is gone, permanently, for that set of accounts.
So the date that belongs in your calendar is not "file by 30 September". It is "by 30 September, either file or ask for more time", and those are two very different amounts of work. One is a year of bookkeeping. The other is a form.
Three things that get an application refused
Companies House is judging whether an event outside your control stopped you filing. The event is what is being assessed, not the inconvenience. Their own published examples are an unexpected illness, or a fire that destroyed the company records a few days before the deadline.
What goes wrong:
- Ordinary delay dressed up as an emergency. This is the commonest refusal. Being busy, a client paying late, a bookkeeper being slow: none of these are events outside your control in the sense meant here.
- A reason with no dates in it. If nobody can line your event up against your deadline, nobody can check that it caused anything.
- Anything you could not evidence if they asked. Supporting documents are optional on the form. Being able to produce them is not.
There is a fourth mistake that is not about the form at all: do not down tools while you wait for a decision. Companies House tells you to carry on preparing the accounts regardless, and if the answer comes back no, you have burned the days you had left.
The ceiling no reason gets you past
The law caps the whole filing period at twelve months from your accounting reference date. If your period ended on 15 January, nothing later than 15 January the following year can be granted, however good your reason and however sympathetic the reviewer.
So the extension is real, but finite. If your deadline is already eleven months out from your period end, there is very little left to give you, and it is better to know that now than on the day you apply.
Where I ended up
The tool is Duck Tax, and it is mine, so take that as disclosed. It is a free micro-entity accounts checker: seven figures in, a validated FRS 105 balance sheet out, no account needed and nothing sent anywhere unless you ask for it. Its MCP server has a tool that answers the only question that matters on the day you find out, which is whether the extension window is still open and how many days are left in it.
Being precise about the limits, because this is exactly the area where vague marketing does real damage: it prepares an application, it cannot submit one, and it does not file accounts with anybody. A director makes the application on Companies House's own service, and the checked numbers go to whoever does your filing. None of this is accounting advice.
Honestly, if you take one thing from this post, let it be the calendar entry rather than the tool. Put the real date in: not the filing deadline, but the last day you can still ask for more time. They are the same day, and that is the problem.
Check your figures free at ducktax.com
Jake
