Company Accounts & Filing Deadlines Every Director Must Know

SLBS
4 days ago
7 min read

Welcome to Company Accounts & Filing Deadlines Every Director Must Know – your straightforward, no-jargon guide to staying compliant in 2026/27.

One late filing can cost you £1,500+ in penalties – and that’s before you count late payment interest, director disqualification risks, or the stress of an HMRC or Companies House investigation.

This factsheet cuts through the confusion with a clear checklist of every statutory deadline you need to know for Companies House and HMRC, the key differences between micro-entity and small company filing options, and a handy printable 12-month compliance calendar you can pin on your wall or keep in your diary.

Whether you’re a sole director or running a small team, you’ll finish this guide knowing exactly what must be filed and when – so you can relax and focus on growing your business instead of chasing paperwork.

Remember, every company’s situation is unique – this is general guidance only. For advice tailored to your company, we strongly recommend speaking to a professional accountant.

Section 1: Companies House Deadlines (Confirmation Statement, Accounts, etc.)

Companies House is the official register for all UK limited companies. Missing a deadline here can trigger automatic penalties, public record issues, and even director disqualification risks. Here are the key statutory deadlines every director must know for 2026/27.

Confirmation Statement (CS01)

Every company (including dormant ones) must file a confirmation statement at least once every 12 months.

Your review period runs for 12 months from the date of incorporation or the date of your last confirmation statement.
You must file within 14 days of the end of that review period.
You can file early at any time – doing so starts a new 12-month review period.
Important 2026/27 update: Directors and persons with significant control (PSCs) must complete identity verification as part of the process (transitional rules apply until November 2026).

Tip: Set a recurring diary reminder for your exact anniversary date.

Annual Accounts

All companies must file full statutory accounts every year – even if dormant or not trading.

Private limited companies: File within 9 months of your accounting reference date (year-end).
First accounts after incorporation: Due within 21 months of incorporation (or 9 months after your accounting reference date – whichever is later).
Example: If your year-end is 31 March 2026, accounts must be filed by 31 December 2026.

Late filing penalties (automatic and non-negotiable):

Up to 1 month late: £150
1–3 months late: £375
3–6 months late: £750
Over 6 months late: £1,500

Other Key Filings (all within 14 days of the change)

Appointment or resignation of directors
Changes to PSC register
Change of registered office address
Allotment of new shares or changes to share capital
Creation or satisfaction of charges (some within 21 days)

Pro tip: Any change to your company details must be reported quickly – even small updates like a new director’s address.

These Companies House deadlines are completely separate from HMRC requirements (covered in Section 2). Missing them doesn’t just cost money – it can damage your company’s credibility with banks, suppliers, and customers.

In the next section we cover the equally important HMRC deadlines for Corporation Tax returns, payments and iXBRL tagging.

Section 2: HMRC Deadlines (CT600, iXBRL, Payments)

HMRC deadlines are completely separate from Companies House and carry their own automatic penalties, interest charges, and potential director liability. Here are the key ones every director must hit in 2026/27.

Corporation Tax Return (CT600)

Must be filed within 12 months of the end of your accounting period.
Example: Year-end 31 March 2026 → CT600 due by 31 March 2027.
From 1 April 2026 the old HMRC/Companies House joint online service closes. You must use commercial software to file (no more free online filing).

Late filing penalties (automatic):

Up to 3 months late: £100
3–6 months late: £200
6–12 months late: £300 + 10% of tax due
Over 12 months late: £300 + 20% of tax due (or more if deliberate)

Payment of Corporation Tax

Due 9 months and 1 day after the end of your accounting period.
Example: Year-end 31 March 2026 → payment due by 1 January 2027.
If your company (or group) has profits over £1.5 million, you may need to pay by quarterly instalments.

Interest is charged daily on late payments (currently around 7–8%).

iXBRL Filing Requirements

All Company Tax Returns and supporting accounts must be filed in iXBRL format (inline eXtensible Business Reporting Language).
This has been mandatory for years, but from April 2026 it becomes even more important because the old simple online service disappears.
Your accountant or software will handle the tagging – just make sure you use compliant software.

Pro tip: Set two reminders for every deadline – one 30 days before and one 7 days before. Many directors get caught out by the 12-month filing window because it falls after the payment date.

Next, Section 3 explains the important differences between micro-entity and small company filing options – because the wrong choice can mean filing far more information than you need to.

Section 3: Micro-entity vs Small Company Filing Options

Most limited companies in the UK qualify for simplified accounts filing at Companies House. Choosing the right option can dramatically reduce the amount of information you have to make public, saving time and protecting your privacy from competitors, suppliers and credit agencies.

Eligibility Thresholds (for periods starting on or after 6 April 2025 / 2026/27 filings)

Criteria	Micro-entity	Small company
Annual turnover	£1 million or less	£15 million or less
Balance sheet total	£500,000 or less	£7.5 million or less
Average employees	10 or fewer	50 or fewer
Qualification rule	Meet at least 2 of the 3 criteria	Meet at least 2 of the 3 criteria

Note: If your company qualifies as a micro-entity, it automatically also qualifies as small – you can choose the simpler micro-entity route.

What You Actually File at Companies House

Micro-entity accounts – Only a simplified balance sheet + very minimal notes – No profit and loss account is filed publicly – No directors’ report required – Shortest and most private option
Small company accounts (if not micro) – Abridged balance sheet + limited notes – No full profit and loss account filed publicly – Optional directors’ report (usually not filed) – Still far less disclosure than medium or large companies

Both options give you full audit exemption (no need for an external auditor).

Advantages of Choosing Micro-entity Filing

Maximum privacy (competitors see almost nothing)
Quickest to prepare and file
Lowest risk of sensitive information leaking
Perfect for sole directors, freelancers and very small teams

When You Might Choose Small Company Instead

You want slightly more detailed notes (e.g. for bank or investor purposes)
Your company is growing and likely to exceed micro-entity thresholds next year

Director Tip: Once you qualify, you can usually keep the status for two years even if you briefly exceed a threshold (the “two-year rule”). Check your exact figures every year-end – it only takes five minutes and can save you hours of extra disclosure.

In Section 4 we give you a ready-to-print 12-month compliance calendar so you’ll never miss a Companies House or HMRC deadline again.

Section 4: 12-Month Compliance Calendar

Print this page and pin it to your wall or add the dates straight into your calendar.

Tip: Replace the example dates below with your own accounting reference date (year-end) and confirmation statement anniversary.

Your Quick-Reference 2026/27 Compliance Calendar

(Example based on 31 March 2026 year-end – adjust as needed)

Month	Date	Deadline / Action	Who it goes to	Penalty if late
April 2026	14 April	Confirmation Statement (if anniversary falls here)	Companies House	£50–£150 + public record issues
June 2026	30 June	Corporation Tax payment (if year-end 31 Mar)	HMRC	Daily interest (~7–8%)
July 2026	31 July	Confirmation Statement reminder	–	–
August 2026	–	No major deadlines	–	–
September 2026	–	–	–	–
October 2026	–	–	–	–
December 2026	31 December	Full accounts to Companies House (9 months)	Companies House	£150 → £1,500 automatic
January 2027	1 January	Corporation Tax payment (if quarterly instalments)	HMRC	Daily interest
February 2027	–	–	–	–
March 2027	31 March	Corporation Tax Return (CT600) (12 months)	HMRC	£100 → £300 + 10–20% of tax
April 2027	14 April	Next Confirmation Statement (new cycle)	Companies House	£50–£150
Ongoing	Within 14 days	Any change (director, PSC, address, shares)	Companies House	£50–£5,000 + possible prosecution

Recurring Deadlines You Must Diarise Every Year

Confirmation Statement – exactly every 12 months + 14 days
Statutory accounts – 9 months after your year-end
Corporation Tax Return – 12 months after your year-end
Corporation Tax payment – 9 months + 1 day after your year-end
Any company change – 14 days (director, PSC, registered office, shares, charges)

Pro tip: Set two reminders for every deadline – one 30 days before and one 7 days before. Many directors miss the 12-month CT600 filing window because it falls long after the payment date.

Ready to never miss a deadline again? In the Conclusion we’ll show you how Suzanne Lock Business Services can take all of this off your plate completely.

Conclusion

You now have everything you need to stay fully compliant in 2026/27 – a complete checklist of Companies House and HMRC deadlines, the smart choice between micro-entity and small company accounts, and a ready-to-print 12-month calendar you can use straight away.

One late filing really can cost £1,500+ in penalties, plus interest, stress, and potential director issues. But with the right systems and reminders, staying on top of it all becomes simple and automatic.

Let us handle it for you

Book your free discovery call with Suzanne Lock Business Services today. We’ll take care of all your Companies House filings, Corporation Tax returns, accounts preparation, iXBRL tagging, and deadline reminders – so you never have to worry about missing anything again.

Book instantly online at https://www.suzannelock.com/booking-calendar

We look forward to making compliance effortless for you.