Most directors don’t think about their company accounts until a letter from Companies House lands on the doormat. By then the year is over the bank statements are a year out of date, and the invoices are scattered across an email inbox a shoebox and three different apps. The deadline is fixed the penalties go up the longer you leave it and the work doesn’t get any smaller by ignoring it.
That’s the real reason accounts preparation matters. It isn’t just a compliance chore. The numbers you file are the official record of how your company performed, they feed directly into your tax bill, and they’re public for anyone to look up. Get them right and the year closes quietly. Get them wrong and you can end up paying penalties, overpaying tax, or explaining yourself to a lender who pulled your accounts before deciding whether to give you a loan.
Here’s how the process actually works and where people usually come unstuck.
What “statutory accounts” really means
Every UK limited company has to prepare a set of annual accounts, often called statutory accounts, from its financial records at the end of each financial year. These aren’t the same as the management figures you might run during the year to check cash flow. Statutory accounts follow a set format and have to comply with UK accounting standards, which is why they look the way they do.
A full set normally includes a balance sheet (what the company owns and owes on the last day of the year), a profit and loss account (income minus costs over the year), notes that explain the figures, and a directors’ report. Smaller companies file a cut-down version, which we’ll come to.
The directors are legally responsible for these accounts being correct, even if someone else does the actual preparation. That responsibility doesn’t transfer to your accountant or your bookkeeper. It stays with you.
The deadlines that catch people out
There are two separate filings, with two separate deadlines, going to two different places. This is where a lot of the confusion starts.
Companies House wants your accounts within nine months of your financial year end. So if your year ends on 31 March, your accounts are due by 31 December. Newly formed companies get longer for their first set: 21 months from the date of incorporation, because the first period is often longer than a standard year.
HMRC is the other one. Your Company Tax Return, the CT600, is due within 12 months of the end of your accounting period. But the tax itself has to be paid earlier, usually within nine months and one day of the period end. That catch trips up a surprising number of directors. You can have months left to file the return while the payment is already overdue.
Missing the Companies House deadline triggers an automatic penalty, and it climbs the longer you wait. For a private company it starts at £150 if you’re up to a month late and rises to £1,500 once you’re more than six months past the date. File late two years running and the penalty doubles. None of this is discretionary, and “I forgot” doesn’t get it waived.
Your company’s size decides how much you actually file
Not every company files the same thing. The amount of detail you have to put on the public record depends on how big the company is, and most owner-managed companies fall into the smaller categories.
Broadly, the law splits companies into micro-entities, small, medium and large, based on turnover, balance sheet total and number of employees. The thresholds were raised in 2025, so a lot of companies that used to count as small now qualify as micro, and some that were medium are now treated as small. It’s worth checking which bracket you fall into for your current year, because the figures have moved.
What this means in plain terms:
- A micro-entity can file very short accounts with minimal detail, sometimes just a simplified balance sheet.
- A small company can usually file reduced accounts and may not need an audit.
- Medium and large companies file fuller accounts, and audit requirements start to bite.
For most contractors, consultants and small trading companies, this is good news. You’re rarely obliged to publish a detailed breakdown of your profit for competitors to read. That said, the rules here are changing (more on that at the end), so don’t assume this year’s filing will look exactly like last year’s.From a year of paperwork to a finished set of accounts
The accounts themselves are the end of the process, not the start. Before anyone can produce them, the underlying records have to be in order. This is the part that takes the time, and it’s the part people underestimate.
In practice, preparing a set of accounts usually runs like this. First the bookkeeping is brought fully up to date, with every sale and purchase recorded and categorised. Then the bank accounts are reconciled, meaning the figures in your books are matched against what actually went through the bank, so nothing is missed or counted twice. After that come the adjustments that don’t show up in the bank feed: depreciation on equipment, money owed to you that hasn’t been paid yet, costs you’ve incurred but not yet been invoiced for, stock on hand, and so on. Only once all of that is settled can the balance sheet and profit and loss be drawn up and the accounts finalised.
Take a small consultancy with a 31 March year end. The director invoices clients, pays a few subscriptions, and draws a modest salary plus dividends. Simple enough on the surface. But the laptop bought in June needs to be capitalised and depreciated rather than written off in one go, the March invoice paid in April still belongs to the old year, and the dividends only count if there were enough retained profits to cover them and the paperwork was done properly at the time. Miss those and the accounts are wrong even though the bank balance looks fine.
The mistakes that quietly cost directors money
A clean set of accounts saves you money in ways that aren’t always obvious. A messy one does the opposite. The errors below come up again and again:
- Treating the company bank account like a personal one, then having to untangle what was a genuine business cost and what was drawings.
- Taking dividends without enough distributable profit to support them, which can turn them into something HMRC treats very differently.
- Missing allowable expenses, so the company pays more corporation tax than it needed to.
- Forgetting that the corporation tax payment deadline comes before the filing deadline.
- Leaving everything to the accountant in the last fortnight, which limits what they can do to help and usually costs more.
Most of these aren’t caused by dishonesty or even carelessness. They’re caused by record-keeping being left until the year is already over, when the detail has faded and the receipts have gone missing.
Where the accounts and your tax bill meet
The accounts and the corporation tax return are closely linked, but they’re not the same document and they don’t always show the same profit. Your accounting profit is worked out under accounting standards. Your taxable profit is worked out under tax rules, which treat some things differently. Client entertaining, for example, is a real cost in your accounts but isn’t deductible for tax. Capital allowances replace the depreciation figure in your accounts with a different calculation for tax purposes.
This is why the order matters. The accounts get prepared first, then the taxable profit is calculated from them, then the tax return is filed and the tax is paid. If the accounts are wrong, the tax figure built on top of them will be wrong too. It’s one reason rushing the accounts to hit a deadline tends to backfire.
Doing it yourself or bringing in an accountant
There’s no legal requirement to hire an accountant. A confident director with simple affairs and good software can file their own accounts and tax return, and plenty do. The free Companies House and HMRC tools will even let small companies file both together in one go.
The question is whether it’s worth your time and whether you’re confident the result is right. The areas that go wrong are rarely the data entry. They’re the judgement calls: what counts as capital, how to handle a director’s loan, whether dividends were legal, how to claim allowances correctly. Get one of those wrong and the saving from doing it yourself disappears.
If your company is dormant, or genuinely tiny with a handful of transactions, doing it yourself is reasonable. As soon as there’s a payroll, a vehicle, stock, a property, or anything that needs a real decision rather than just recording a number, the case for getting help gets much stronger. At Interface Accountants this is the bulk of what we do: taking a year of records, sorting out the judgement calls, and filing accounts that are correct and on time so the deadline stops being something you dread.
The takeaway and what’s changing
If you remember nothing else: keep your records current through the year, know your two deadlines, and don’t treat the tax payment date as if it’s the same as the filing date. That alone avoids most of the trouble directors run into.
It’s also worth knowing the rules are shifting. Companies House is in the middle of a reform programme that will change how accounts are filed. Software filing is set to become mandatory, and smaller companies are likely to have to show more detail than the stripped-back accounts they file today. The timelines have moved more than once, so check the current position for your next year end rather than assuming the old approach still applies. Sorting your bookkeeping out now puts you in a far easier position whenever those changes land.
FAQs
When are my limited company accounts due?
Within nine months of your financial year end for Companies House. First accounts for a new company are due 21 months after the date of incorporation. Your tax return to HMRC is due within 12 months of the period end, but the tax is payable within nine months and one day.
Do I legally need an accountant to prepare my accounts?
No. Directors can prepare and file their own accounts. Most owner-managed companies use an accountant because the judgement areas, such as capital allowances and dividends, are easy to get wrong and expensive to fix.
What’s the difference between my Companies House accounts and my tax return?
Companies House accounts are the public financial record prepared under accounting standards. The tax return calculates what you owe HMRC using tax rules, which treat some costs differently. The accounts are prepared first, then the tax figure is worked out from them.
What happens if I file my accounts late?
Companies House issues an automatic penalty starting at £150 and rising to £1,500 the further past the deadline you go. The penalty doubles if you file late two years in a row, and late filing can also affect your standing with lenders.
My company is dormant. Do I still have to file?
Yes. Dormant companies still have to file dormant accounts with Companies House each year and a confirmation statement. The filing is simpler, but skipping it still leads to penalties.