UK LTD Filing Deadlines 2026: Avoid Costly HMRC & Companies House Penalties
Miss a Deadline, Pay the Price
Running a UK Limited company from Poland comes with real responsibilities. Among the most overlooked — and most expensive — are the statutory filing deadlines imposed by HMRC and Companies House. Missing them isn’t just a slap on the wrist. It can cost you hundreds or even thousands of pounds.
This guide walks you through every key deadline for UK LTD companies in 2026, the penalties for late filing, and how to stay compliant without losing sleep.
The Three Critical Filing Deadlines Every LTD Must Meet
1. Annual Accounts — Companies House
Deadline: 9 months after the end of your company’s financial year.
Your company’s financial year-end is usually the anniversary of incorporation. For example, if you incorporated on 15 March 2025, your first accounting period likely ends 31 March 2026. You must file your Annual Accounts with Companies House by 31 December 2026 (9 months later).
2. Company Tax Return (CT600) — HMRC
Deadline: 12 months after the end of your accounting period.
This is separate from the Annual Accounts. The CT600 reports your company’s taxable profits to HMRC. Even if your company made no profit, you must file. The deadline is 12 months after the accounting period ends — but note that any Corporation Tax owed must be paid within 9 months and 1 day.
3. Confirmation Statement — Companies House
Deadline: Every 12 months from incorporation (or from the last statement).
Think of this as your company’s annual “check-in”. It confirms that Companies House has the correct information about your directors, shareholders, registered office, and share capital. You get a 14-day window to file — miss it, and you face penalties (and potential strike-off).
What Happens If You’re Late? The Penalty Scale
| Delay | Penalty (Private LTD) |
|---|---|
| Up to 1 month | £150 |
| 1–3 months | £375 |
| 3–6 months | £750 |
| 6+ months | £1,500 |
Double penalties apply if you were late the previous year too. Companies House can also strike your company off the register entirely.
HMRC has its own penalty regime: late CT600 filing starts at £100, escalates to £200 after 3 months, plus daily penalties and interest on unpaid Corporation Tax.
The Confirmation Statement Trap
Many Polish entrepreneurs treat the Confirmation Statement as optional. It isn’t. Companies House sends a reminder to your registered office address — but if that address isn’t monitored, you might never see the reminder. The fee is just £13 online, but non-filing can lead to compulsory strike-off.
How to Stay Compliant: A Simple Timeline
- After incorporation: Note your accounting reference date (ARD) — usually the last day of the month, 12 months after incorporation.
- 9 months after ARD: File Annual Accounts at Companies House.
- 12 months after ARD: File CT600 at HMRC.
- Every 12 months: File Confirmation Statement.
- 9 months + 1 day after ARD: Pay any Corporation Tax owed.
Mark these in your calendar. Better yet — let a professional handle it.
Why Polish Entrepreneurs Choose Professional UK Accounting
HMRC and Companies House deadlines are non-negotiable. The systems, forms, and terminology differ from Polish accounting. A cross-border mistake — like confusing the ARD with the tax year — can trigger compliance issues.
At Semper Paratus Legal House LLP, we specialise in UK company accounting for Polish entrepreneurs. Our monthly service starts at 400 PLN and includes Annual Accounts, CT600, Confirmation Statement, and a dedicated account manager who monitors every deadline.
Book a Free Consultation
Don’t wait until a penalty notice lands. Let’s review your LTD’s filing calendar together — free of charge.
📞 UK: +44 745 638 6117
📞 PL: +48 530 447 230
📧 Email: [email protected]
📅 Book online: https://calendly.com/semperparatus/
Semper Paratus Legal House LLP
42-44 Bishopsgate, EC2N 4AH, London, United Kingdom
Disclaimer: This article is for informational purposes only and does not constitute legal or tax advice. Deadlines and penalties are accurate as of 2026 but may change. Always consult a qualified professional for your specific situation.
