A limited company files three things on different clocks. You send your annual accounts to Companies House, due nine months after your financial year-end (your very first accounts are due 21 months after the date of incorporation). You send a Company Tax Return, the CT600, to HMRC, due 12 months after the end of your accounting period. And you file a confirmation statement with Companies House each year. The quirk that catches directors out: your Corporation Tax has to be paid nine months and one day after your year-end — before the CT600 that works it out is even due. Miss the accounts deadline and Companies House charges an automatic penalty, from £150 rising to £1,500, doubled if you file late two years running. Put all four dates in the diary the week you incorporate and none of it should surprise you.
Deadlines and penalties here are sourced to gov.uk and current for 2026/27; company law and filing fees change, so check the exact dates against your own year-end. General guidance, not personal advice.
What does a limited company have to file — and to whom?
It helps to treat these as three separate jobs rather than one big "tax thing", because they go to two different organisations on two different timetables. Muddling them is the most common reason a director thinks they are up to date when they are not.
Your annual accounts are your statutory year-end accounts — a balance sheet, a profit-and-loss account and the notes that go with them — and they go to Companies House. Most small companies can file in a reduced form, but the deadline is the same either way.
Your Company Tax Return, known as the CT600, goes to HMRC. It reports the company's taxable profit and works out the Corporation Tax due on it. For 2026/27 the rates run from 19% on profits up to £50,000 to 25% above £250,000, with marginal relief in between — our guide to Corporation Tax for directors sets those out in full.
Your confirmation statement, the CS01, goes to Companies House once a year and carries a £50 fee. It confirms that the details on the public register — registered office, directors, shareholders and people with significant control — are still correct. It is not your accounts and not a tax return; that mix-up is the one we untangle most, so it is worth reading what a confirmation statement is on its own terms.
Put together, that is three filings going to two bodies, each on its own clock:
What you file (or pay)
Who to
Deadline
Annual accounts
Companies House
9 months after your financial year-end
First annual accounts
Companies House
21 months after the date of incorporation
Company Tax Return (CT600)
HMRC
12 months after the end of your accounting period
Corporation Tax payment
HMRC
9 months and 1 day after the accounting period
Confirmation statement (CS01, £50)
Companies House
At least once every 12 months
When are the deadlines?
The dates are fixed by law and counted from two different starting points — your financial year-end for the accounts, and the end of your accounting period for the tax. For most companies those line up, but the gaps between them are where directors come unstuck.
Your annual accounts are due 9 months after the end of your financial year (gov.uk). Your first accounts are the exception: they are due 21 months after the date of incorporation, because a company's first accounting period usually runs longer than a single year (gov.uk). After that first set, you settle into the nine-month rhythm every year.
Your Company Tax Return (CT600) is due 12 months after the end of your accounting period (gov.uk). Here is the part that trips people up: the Corporation Tax itself is due 9 months and 1 day after the end of your accounting period — three months before the return that calculates it (companies with larger profits pay in instalments). In practice that means you, or your accountant, work out the tax and prepare the accounts and CT600 together, well ahead of the return deadline, so the figure is ready to pay on time. The tax comes first; the paperwork follows.
If you would rather have every date and form in one place before your first year-end comes round, our free guide sets out the limited-company filing calendar and what each return asks of you.
Late filing has consequences on both sides, and the Companies House one is automatic — no reminder call, no discretion. The penalty for late accounts starts at £150 and climbs with every month you leave it.
For a private company, the Companies House penalties for late annual accounts are:
How late your accounts are
Penalty (private company)
Up to 1 month
£150
More than 1 to 3 months
£375
More than 3 to 6 months
£750
More than 6 months
£1,500
Those figures double if you file late two years running (gov.uk). HMRC also penalises a late Company Tax Return, with the charge starting the day after the deadline and increasing the longer the return is outstanding, plus interest on any Corporation Tax paid late — we have kept those amounts general here because they escalate and depend on the delay. Beyond the money, persistent non-filing puts the company at risk of being struck off the register altogether.
One thing worth flagging: pausing the business does not switch the obligations off. Even a dormant company still files dormant accounts and a confirmation statement, so "we did no trading" is not a defence — if that is your situation, read what a dormant company is and what it still has to submit.
Penalties climb the longer you leave it, and they double if it happens two years in a row — being matched with an accountant whose job is to watch those dates is the cheapest insurance against them.
Legally, no — you can prepare and file both your accounts and your CT600 yourself, through the Companies House and HMRC online services, and plenty of single-director companies with straightforward affairs do exactly that. Whether you should is a different question.
Most directors use an accountant for two reasons: accuracy — getting the profit and the Corporation Tax right, and claiming what is genuinely allowable — and never missing a deadline. The cost of an accountant is usually less than a single doubled penalty, and it buys back the hours you would otherwise spend wrestling with two filing systems. If you are weighing it up, our honest take on whether you need an accountant sets out where it earns its keep and where it may not.
Go Limited is a connector, not the accountant — we guide the decision and match you with a trusted partner accountant; we do not sign off or file your accounts ourselves. In our experience the date that catches directors out is the Corporation Tax one: it falls due a day after the nine-month mark, ahead of the return that actually works it out, and those two clocks trip people up every single year. A good partner keeps all of it — accounts, CT600, payment and confirmation statement — on one calendar. You can see how the introductions work on our accountancy page.
Three filings, two organisations, and a Corporation Tax bill that falls due before the return that calculates it — the companies that never get caught out are the ones that mapped all four dates the week they incorporated. Tell us your year-end and what your company does, and we will connect you with a partner accountant who keeps the accounts, the CT600 and the payment date all on schedule.
What accounts does a limited company have to file?
Every limited company files annual (statutory) accounts with Companies House — normally a balance sheet, a profit-and-loss account and notes, though smaller companies can file in a reduced form. Separately, it files a Company Tax Return (the CT600) with HMRC and a confirmation statement with Companies House each year. Even a dormant company still has to file dormant accounts and a confirmation statement.
When are limited company accounts due?
Annual accounts are due nine months after the end of your financial year. Your very first accounts are the exception — they are due 21 months after the date of incorporation, because a company's first accounting period usually runs longer than a year. Your Company Tax Return has its own, later deadline of 12 months after the accounting period, but the Corporation Tax is payable earlier.
Can I do my own limited company accounts?
Yes — you can prepare and file both your accounts and your CT600 yourself through the Companies House and HMRC online services, and plenty of directors with simple affairs do. Most, though, use an accountant to get the profit and Corporation Tax right, claim what is allowable and keep the deadlines. Go Limited is not the accountant; we match you with a trusted partner if you would rather hand it over.
What's the penalty for filing accounts late?
Companies House charges an automatic penalty for late annual accounts: £150 up to a month late, £375 for one to three months, £750 for three to six months and £1,500 beyond six months, for a private company. The penalty doubles if you file late two years in a row. HMRC separately penalises a late Company Tax Return, with the charge rising the longer it stays outstanding.
What's the difference between accounts and a tax return?
Your annual accounts report the company's financial position to Companies House and largely go on the public register. Your Company Tax Return (CT600) goes only to HMRC and works out the Corporation Tax on your profit. They draw on overlapping figures but serve different bodies and carry different deadlines — and neither is the same as the confirmation statement, which only confirms your company details are current.
A limited company files three things on different clocks. You send your annual accounts to Companies House, due nine months after your financial year-end (your very first accounts are due 21 months after the date of incorporation). You send a Company Tax Return, the CT600, to HMRC, due 12 months after the end of your accounting period. And you file a confirmation statement with Companies House each year. The quirk that catches directors out: your Corporation Tax has to be paid nine months and one day after your year-end — before the CT600 that works it out is even due. Miss the accounts deadline and Companies House charges an automatic penalty, from £150 rising to £1,500, doubled if you file late two years running. Put all four dates in the diary the week you incorporate and none of it should surprise you.
Deadlines and penalties here are sourced to gov.uk and current for 2026/27; company law and filing fees change, so check the exact dates against your own year-end. General guidance, not personal advice.
What does a limited company have to file — and to whom?
It helps to treat these as three separate jobs rather than one big "tax thing", because they go to two different organisations on two different timetables. Muddling them is the most common reason a director thinks they are up to date when they are not.
Your annual accounts are your statutory year-end accounts — a balance sheet, a profit-and-loss account and the notes that go with them — and they go to Companies House. Most small companies can file in a reduced form, but the deadline is the same either way.
Your Company Tax Return, known as the CT600, goes to HMRC. It reports the company's taxable profit and works out the Corporation Tax due on it. For 2026/27 the rates run from 19% on profits up to £50,000 to 25% above £250,000, with marginal relief in between — our guide to Corporation Tax for directors sets those out in full.
Your confirmation statement, the CS01, goes to Companies House once a year and carries a £50 fee. It confirms that the details on the public register — registered office, directors, shareholders and people with significant control — are still correct. It is not your accounts and not a tax return; that mix-up is the one we untangle most, so it is worth reading what a confirmation statement is on its own terms.
Put together, that is three filings going to two bodies, each on its own clock:
What you file (or pay)
Who to
Deadline
Annual accounts
Companies House
9 months after your financial year-end
First annual accounts
Companies House
21 months after the date of incorporation
Company Tax Return (CT600)
HMRC
12 months after the end of your accounting period
Corporation Tax payment
HMRC
9 months and 1 day after the accounting period
Confirmation statement (CS01, £50)
Companies House
At least once every 12 months
When are the deadlines?
The dates are fixed by law and counted from two different starting points — your financial year-end for the accounts, and the end of your accounting period for the tax. For most companies those line up, but the gaps between them are where directors come unstuck.
Your annual accounts are due 9 months after the end of your financial year (gov.uk). Your first accounts are the exception: they are due 21 months after the date of incorporation, because a company's first accounting period usually runs longer than a single year (gov.uk). After that first set, you settle into the nine-month rhythm every year.
Your Company Tax Return (CT600) is due 12 months after the end of your accounting period (gov.uk). Here is the part that trips people up: the Corporation Tax itself is due 9 months and 1 day after the end of your accounting period — three months before the return that calculates it (companies with larger profits pay in instalments). In practice that means you, or your accountant, work out the tax and prepare the accounts and CT600 together, well ahead of the return deadline, so the figure is ready to pay on time. The tax comes first; the paperwork follows.
If you would rather have every date and form in one place before your first year-end comes round, our free guide sets out the limited-company filing calendar and what each return asks of you.
Late filing has consequences on both sides, and the Companies House one is automatic — no reminder call, no discretion. The penalty for late accounts starts at £150 and climbs with every month you leave it.
For a private company, the Companies House penalties for late annual accounts are:
How late your accounts are
Penalty (private company)
Up to 1 month
£150
More than 1 to 3 months
£375
More than 3 to 6 months
£750
More than 6 months
£1,500
Those figures double if you file late two years running (gov.uk). HMRC also penalises a late Company Tax Return, with the charge starting the day after the deadline and increasing the longer the return is outstanding, plus interest on any Corporation Tax paid late — we have kept those amounts general here because they escalate and depend on the delay. Beyond the money, persistent non-filing puts the company at risk of being struck off the register altogether.
One thing worth flagging: pausing the business does not switch the obligations off. Even a dormant company still files dormant accounts and a confirmation statement, so "we did no trading" is not a defence — if that is your situation, read what a dormant company is and what it still has to submit.
Penalties climb the longer you leave it, and they double if it happens two years in a row — being matched with an accountant whose job is to watch those dates is the cheapest insurance against them.
Legally, no — you can prepare and file both your accounts and your CT600 yourself, through the Companies House and HMRC online services, and plenty of single-director companies with straightforward affairs do exactly that. Whether you should is a different question.
Most directors use an accountant for two reasons: accuracy — getting the profit and the Corporation Tax right, and claiming what is genuinely allowable — and never missing a deadline. The cost of an accountant is usually less than a single doubled penalty, and it buys back the hours you would otherwise spend wrestling with two filing systems. If you are weighing it up, our honest take on whether you need an accountant sets out where it earns its keep and where it may not.
Go Limited is a connector, not the accountant — we guide the decision and match you with a trusted partner accountant; we do not sign off or file your accounts ourselves. In our experience the date that catches directors out is the Corporation Tax one: it falls due a day after the nine-month mark, ahead of the return that actually works it out, and those two clocks trip people up every single year. A good partner keeps all of it — accounts, CT600, payment and confirmation statement — on one calendar. You can see how the introductions work on our accountancy page.
Three filings, two organisations, and a Corporation Tax bill that falls due before the return that calculates it — the companies that never get caught out are the ones that mapped all four dates the week they incorporated. Tell us your year-end and what your company does, and we will connect you with a partner accountant who keeps the accounts, the CT600 and the payment date all on schedule.
What accounts does a limited company have to file?
Every limited company files annual (statutory) accounts with Companies House — normally a balance sheet, a profit-and-loss account and notes, though smaller companies can file in a reduced form. Separately, it files a Company Tax Return (the CT600) with HMRC and a confirmation statement with Companies House each year. Even a dormant company still has to file dormant accounts and a confirmation statement.
When are limited company accounts due?
Annual accounts are due nine months after the end of your financial year. Your very first accounts are the exception — they are due 21 months after the date of incorporation, because a company's first accounting period usually runs longer than a year. Your Company Tax Return has its own, later deadline of 12 months after the accounting period, but the Corporation Tax is payable earlier.
Can I do my own limited company accounts?
Yes — you can prepare and file both your accounts and your CT600 yourself through the Companies House and HMRC online services, and plenty of directors with simple affairs do. Most, though, use an accountant to get the profit and Corporation Tax right, claim what is allowable and keep the deadlines. Go Limited is not the accountant; we match you with a trusted partner if you would rather hand it over.
What's the penalty for filing accounts late?
Companies House charges an automatic penalty for late annual accounts: £150 up to a month late, £375 for one to three months, £750 for three to six months and £1,500 beyond six months, for a private company. The penalty doubles if you file late two years in a row. HMRC separately penalises a late Company Tax Return, with the charge rising the longer it stays outstanding.
What's the difference between accounts and a tax return?
Your annual accounts report the company's financial position to Companies House and largely go on the public register. Your Company Tax Return (CT600) goes only to HMRC and works out the Corporation Tax on your profit. They draw on overlapping figures but serve different bodies and carry different deadlines — and neither is the same as the confirmation statement, which only confirms your company details are current.
