Yes — the CT41G is an important introductory letter (and sometimes form) that HMRC automatically sends to most newly incorporated UK limited companies shortly after registration with Companies House. It serves as your company’s official introduction to the Corporation Tax system, providing your Unique Taxpayer Reference (UTR) number and guiding you on next steps for tax compliance.

Updated March 2026: HMRC has largely moved away from paper forms for standard limited companies. Instead, the CT41G letter now directs you to handle everything online through your Government Gateway account. You must still act promptly — especially if your company has started trading — to register for Corporation Tax within 3 months of beginning business activity. Missing this can lead to penalties, interest on late payments, and complications with your first Company Tax Return (CT600).

At Filing Accounts, we help new directors understand and respond correctly to their CT41G letter, set up online accounts, and stay fully compliant from day one. Contact us today for expert support with your new limited company’s tax obligations.

What Exactly Is the CT41G Form/Letter?

The CT41G is HMRC’s way of acknowledging your company’s incorporation and starting the process of bringing it into the Corporation Tax regime.

It typically includes:

• Your company’s 10-digit Unique Taxpayer Reference (UTR) number — essential for all future Corporation Tax communications and payments.
• Your company’s Tax Office number.
• Clear instructions on how to set up or activate your HMRC online Corporation Tax services.
• Guidance on whether your company is trading, dormant, or non-trading.
• Details about your first Corporation Tax return deadlines and payment obligations.
• Information on how to appoint an agent (such as an accountant) to handle your tax affairs.

Note: For most standard limited companies, the traditional paper “CT41G form” has been phased out. You now receive a letter with instructions to complete everything digitally.

Official GOV.UK reference: Corporation Tax: trading and non-trading

When and Why Do You Receive a CT41G Letter?

Companies House automatically notifies HMRC when a new company is incorporated. HMRC then sends the CT41G letter to your registered office address, usually within 2–4 weeks.

The letter helps HMRC:

• Assign your company a UTR for tax records.
• Understand whether you intend to trade or remain dormant.
• Set the correct accounting periods and deadlines.
• Ensure you register for Corporation Tax at the right time.

Even if your company is currently dormant (no significant trading activity), you should still respond or notify HMRC to avoid unnecessary follow-ups.

What You Must Do After Receiving the CT41G Letter

Your actions depend on your company’s status:

If Your Company Has Started Trading

• Register for Corporation Tax within 3 months of the date you began business activity.
• Set up your HMRC online Corporation Tax account using the activation code or instructions in the letter.
• Prepare for your first Company Tax Return (CT600), due 12 months after your Accounting Reference Date.

If Your Company Is Dormant (No Trading)

• Notify HMRC that the company is dormant for Corporation Tax purposes as soon as possible. This prevents them from expecting a full tax return.
• You may still need to activate online services for future use.

Pro tip: Even dormant companies must file annual accounts with Companies House and a Confirmation Statement (CS01). The CT41G helps keep your HMRC records accurate.

Step-by-Step: How to Respond to Your CT41G Letter in 2026

1. Read the letter carefully — Note your UTR, Tax Office number, and any deadlines.
2. Create or log into your Government Gateway account — This is required for online Corporation Tax services.
3. Activate or set up Corporation Tax online services — Follow the instructions in the letter (an activation code is often posted separately).
4. Confirm trading status — Tell HMRC whether the company has started trading or remains dormant.
5. Register for Corporation Tax if trading — Do this online via GOV.UK within the 3-month window.
6. Appoint an agent if needed — You can authorise an accountant to handle filings and communications.
7. Keep records — Store the CT41G letter safely with your company documents.

Official registration service: Register for Corporation Tax

Common Questions About the CT41G Form

Do I have to complete and return a paper form? No — for most limited companies, everything is now handled online. Paper forms are mainly used for clubs, societies, or specific cases.

What if I don’t receive the CT41G letter? Contact HMRC or request a copy of your UTR online. Delaying can cause problems later.

Does the CT41G mean my company is automatically registered for Corporation Tax? No — you usually still need to confirm trading status and complete online registration if you have started business activity.

What are the penalties for ignoring the CT41G? You risk late-registration penalties, interest on unpaid tax, and complications with your first tax return. HMRC can also issue penalties for failure to notify.

What Our Clients Say on Trustpilot

• “Filing Accounts explained my CT41G letter clearly and helped me set up everything online quickly. No stress at all!” – Anonymous, March 2026 (5 stars)
• “Professional service from start to finish. They handled the CT41G response and Corporation Tax registration perfectly.” – Mark T., February 2026 (5 stars)
• “Saved me hours of confusion with my new company’s tax setup. Highly recommend!” – Sarah L., January 2026 (5 stars)

With our consistent 4.2/5 Trustpilot rating, new directors trust us to guide them through these important early steps.

Frequently Asked Questions

How soon after incorporation will I receive the CT41G? Usually within 2–4 weeks, sent to your registered office address.

Do dormant companies need to respond to the CT41G? Yes — notify HMRC of your dormant status to avoid unnecessary tax returns.

Can I appoint an accountant to deal with the CT41G? Yes — authorising an agent makes the process much simpler and reduces the risk of errors.

What information do I need to provide? Details such as trading status, accounting periods, contact information, and whether you want to appoint an agent.

Official GOV.UK resources:

• Corporation Tax: trading and non-trading
• Register for Corporation Tax
• Set up HMRC online services

Need Help with Your CT41G Letter and Corporation Tax Setup?

Receiving your first CT41G letter can feel overwhelming, but it doesn’t have to be. Filing Accounts provides clear, practical support to ensure your new limited company is correctly registered for Corporation Tax and fully compliant from the start.

Contact us today or book a free consultation — we’ll review your CT41G letter, handle online setup, and take care of all your early tax obligations in 2026.