Running a limited company comes with a compliance calendar that never really stops. Every year, the same deadlines come around — and missing any of them can mean penalties, fines, or worse, your company being struck off the register.
The confusion for many directors is that Companies House and HMRC are two completely separate organisations with separate filing requirements and separate deadlines. What you send to one is not automatically shared with the other, and the two sets of obligations don’t always align neatly.
This article lays out exactly what a limited company must file, where it goes, and when — so you’ve got a clear reference to work from.
Companies House vs HMRC: Understanding the Difference
Before getting into the deadlines, it helps to be clear on who requires what.
Companies House is the UK’s registrar of companies. It maintains the public register of all UK limited companies and requires you to keep your company’s information up to date. The filings it cares about are your annual accounts and your confirmation statement — plus any changes to your company’s structure, officers, or registered address.
HMRC is the tax authority. It requires you to file a Corporation Tax return, pay any Corporation Tax due, submit VAT returns if you’re registered, run payroll and submit RTI reports if you have employees, and handle the personal tax affairs of directors through Self Assessment.
Neither body accepts filings meant for the other. Missing a Companies House deadline doesn’t affect your tax position directly, but it does affect your legal standing as a company — and vice versa.
Companies House Deadlines
Annual Accounts
Your annual accounts — also called statutory accounts — must be filed with Companies House every year. For a private limited company, the deadline is 9 months after your accounting reference date (your company’s financial year end).
So if your year end is 31 March, your accounts are due at Companies House by 31 December of the same calendar year.
For a newly incorporated company, your first accounts cover the period from incorporation to your accounting reference date, and you have 21 months from the date of incorporation to file them — giving new businesses a little extra time to get organised.
Our post on limited company year-end accounts covers what your accountant needs from you and when, which is worth reading well before your deadline approaches rather than after it.
Confirmation Statement
The confirmation statement (previously called the annual return) is a snapshot of key information about your company — its registered office, directors, shareholders, share capital, and SIC code. You must file one at least once every 12 months, within 14 days of your confirmation statement due date.
The due date is either the anniversary of incorporation or the anniversary of your last confirmation statement, whichever is more recent.
The confirmation statement doesn’t cost anything if filed online, and it doesn’t require your accounts to be finalised — it’s simply a check that Companies House has accurate information about your company.
Changes to Company Details
Outside of the annual cycle, Companies House must be notified whenever there are changes to your company’s registered details. This includes:
- Appointing or removing a director or secretary
- Changes to a director’s personal details (name, address)
- Changes to your registered office address
- Allotting new shares or transferring existing ones
- Changes to your articles of association
Most of these changes must be notified within 14 days. Share allotments must be reported within one month. These aren’t annual events — they’re triggered whenever the change occurs.
Late Filing Penalties at Companies House
Companies House takes late accounts seriously. The penalties are automatic and start from the day after your deadline:
- Up to 1 month late: £150
- 1 to 3 months late: £375
- 3 to 6 months late: £750
- More than 6 months late: £1,500
These figures double if your accounts were also late in the previous year. Persistent late filing can lead to Companies House initiating proceedings to strike your company off the register — which is a serious and often difficult situation to reverse.
Our article on understanding late filing fees at Companies House goes into the penalty structure in more detail and explains what happens if you miss the deadline.
HMRC Deadlines
Corporation Tax Payment
This one catches directors out regularly because it comes before the filing deadline. Your Corporation Tax payment is due 9 months and 1 day after the end of your accounting period.
So if your year end is 31 March 2025, your Corporation Tax is due by 1 January 2026 — a full three months before your accounts need to be filed with HMRC.
You need to have a reasonable calculation of what you owe and pay it by this date, even if your full accounts aren’t yet finalised. HMRC charges interest on late payments from the day after the due date, and the current rate is notably higher than it was a few years ago.
Corporation Tax Return (CT600)
Your Corporation Tax return — known as a CT600 — must be filed with HMRC within 12 months of the end of your accounting period. This is three months later than the payment deadline, which means you could technically pay before filing — and often should.
The CT600 is more detailed than your Companies House accounts. It includes your corporation tax computation, details of any reliefs claimed, and a breakdown of your taxable income. It must be filed online using HMRC-compatible software.
For most small companies, the CT600 is prepared alongside the statutory accounts. If you work with us to prepare company accounts, we handle both simultaneously — which means your figures are consistent and everything goes in on time.
Common mistakes on CT600s — including errors that cost businesses money — are covered in our article on corporation tax mistakes. It’s a genuinely useful read before your accountant starts work on your return.
VAT Returns
If your company is VAT-registered, VAT returns are due one month and seven days after the end of each VAT period. For most businesses, this means quarterly returns — though annual and monthly schemes exist.
So if your VAT quarter ends 31 March, your return and payment are due by 7 May.
Under Making Tax Digital for VAT, you must keep digital records and submit returns through compatible software — the old HMRC portal is no longer an option. Our MTD for VAT guide explains what’s required, and our vat return filing services handle submission on your behalf each quarter.
PAYE and RTI
If you have employees — including yourself as a director on the payroll — you must submit a Full Payment Submission (FPS) to HMRC on or before every payday. This is the Real Time Information requirement that applies to all employers regardless of size.
Your PAYE liability is due to HMRC by the 19th of the following month (or the 22nd if paying electronically). So for pay periods in April, PAYE is due by 19 May.
You must also submit an Employer Payment Summary (EPS) in any month where you haven’t made payments, or to claim reductions such as Employment Allowance. Missing either submission triggers automatic HMRC notices.
Self Assessment for Directors
Directors are required to file a personal Self Assessment tax return by 31 January following the end of the tax year. For the 2024/25 tax year (ending 5 April 2025), the deadline is 31 January 2026.
This is separate from the company’s CT600 and covers your personal income — including salary, dividends, benefits in kind, and any other income sources. It’s easy to think of the company’s tax return as the main event, but your personal return is equally important and has the same penalty structure for late filing.
If you haven’t registered for Self Assessment before, the deadline to do so is 5 October in the year after the tax year ended.
How the Deadlines Overlap
For a company with a 31 March year end, a typical compliance calendar looks like this:
- 1 January — Corporation Tax payment due (9 months and 1 day after year end)
- 7 of each month — Quarterly VAT return and payment (if applicable)
- 19 of each month — PAYE payment due
- 31 January — Director’s Self Assessment due
- 31 March — CT600 filing deadline (12 months after year end)
- 31 December — Companies House accounts deadline (9 months after year end)
- Within 14 days of anniversary — Confirmation statement due
The overlap between the Corporation Tax payment deadline (January) and the director’s Self Assessment deadline (also January) is worth flagging — January is often the busiest month of the year from a compliance perspective, and leaving things to the last minute means both deadlines become stressful at the same time.
Our article on setting up a limited company in the UK covers how the compliance calendar is established from incorporation, which is particularly useful if your company is relatively new.
What Happens If You Miss a Deadline?
For Companies House, penalties are automatic and scale with how late you are, as covered above. Persistent failure to file can result in the company being struck off.
For HMRC, the consequences depend on which deadline you’ve missed:
Late Corporation Tax payment — Interest accrues from the day after the due date. HMRC may also issue a surcharge notice if payment is significantly late.
Late CT600 — A £100 automatic penalty for filing up to three months late, rising to a further £100 after three months. If the return is more than six months late, HMRC can issue a tax determination and charge a percentage-based penalty.
Late VAT return or payment — Under the new VAT penalty regime (which came in from January 2023), late payments accrue penalty points. Once you reach a threshold, financial penalties apply. Interest is also charged on late payments.
Late Self Assessment — An automatic £100 for missing the 31 January deadline, escalating significantly if the return remains outstanding. Our post on late tax returns and penalties covers the full penalty structure in detail.
Companies House Identity Verification
It’s worth noting that Companies House is in the process of rolling out mandatory identity verification for directors, people with significant control, and anyone who files on behalf of a company. This is part of the reforms brought in under the Economic Crime and Corporate Transparency Act 2023.
Our article on Companies House identity verification explains what the new requirements involve and what you’ll need to do to stay compliant as the rollout continues.
How an Accountant Keeps All of This on Track
The honest answer is that keeping track of all these deadlines yourself — while also running a business — is genuinely difficult. Accounting periods, Companies House anniversaries, VAT quarters, and payroll cycles all move independently, and none of them care that you’re busy.
A good accountant builds a compliance calendar for your company from day one and takes responsibility for hitting every deadline on your behalf. That means:
- Preparing and filing your statutory accounts with Companies House on time
- Calculating and reminding you of your Corporation Tax payment date well in advance
- Filing your CT600 with HMRC within the deadline
- Handling quarterly VAT returns and ensuring digital records are maintained
- Managing payroll and RTI submissions every pay period
- Preparing your director’s Self Assessment and filing it before 31 January
For accountants for sole trader clients who have recently incorporated, this handover from a simpler compliance structure to a full limited company calendar is something we manage carefully — making sure nothing is missed in the transition.
If you’re based in Berkshire, our accountants reading office works with limited companies of all sizes, and our Slough and Wednesbury teams cover clients across the Midlands and beyond.
For businesses that want ongoing visibility of where they stand, we produce regular management reports through QuickBooks — so you can see your financial position between filing dates rather than only finding out at year end. Our financial reporting service gives you that live picture alongside the compliance work.
FAQs
Can I change my company’s accounting reference date? Yes. You can shorten your accounting period as many times as you like, but you can only extend it once every five years (with some exceptions). Changing your year end affects all your downstream deadlines, so it’s worth discussing with your accountant before making any change.
What is a dormant company and does it still need to file? A dormant company — one that has had no significant accounting transactions — still has filing obligations. You must still file a confirmation statement and dormant accounts with Companies House every year. HMRC must also be notified that the company is dormant, and a CT600 may still be required.
Do I need to file accounts with both Companies House and HMRC? Yes, but they’re different documents. Companies House receives your statutory accounts (balance sheet, profit and loss, notes). HMRC receives your CT600 along with full accounts that may include additional detail not required by Companies House.
What is an accounting reference date and can I find out mine? Your accounting reference date is your company’s financial year end. It’s set when the company is incorporated — typically defaulting to the last day of the month in which the company was incorporated, 12 months later. You can look it up on Companies House WebFiling or ask your accountant.
Can HMRC and Companies House deadlines be extended? Companies House can grant extensions in certain circumstances — for example, if your company is affected by an unforeseen event. HMRC has similar provisions. However, extensions are not guaranteed, and applying for one doesn’t protect you from penalties if the extension isn’t granted. It’s always better to file as early as possible.
What happens if my company is struck off? If your company is struck off the Companies House register, it ceases to exist as a legal entity. Any assets belonging to the company become property of the Crown. Restoration is possible but involves a court process and can be costly. It’s a situation well worth avoiding.
Never Miss a Deadline Again
The compliance calendar for a limited company has a lot of moving parts — but with the right support in place, none of it needs to be stressful.
At Asmat & Co, we’re Slough trusted accountants with offices also in Reading and Wednesbury. We manage the full compliance cycle for limited companies — from preparing company accounts and CT600s through to VAT, payroll, and director Self Assessment — all under one roof, with no hidden fees and a guaranteed response to every query within three hours.
If you’re currently managing deadlines yourself and finding it stressful, or if you’ve recently missed a deadline and need help getting back on track, we’re ready to help.
