When you incorporate a limited company at Companies House, you must register it for Corporation Tax with HMRC within three months of the date it starts doing business. This deadline is strict and applies even if the company has not yet earned revenue.
New founders in e-commerce and early-stage startups often focus on product development and sales channels while overlooking basic compliance steps. Understanding the process, required notifications and how accounting periods work helps avoid penalties and keeps your company on a solid legal footing from day one.
When Corporation Tax registration becomes necessary
Incorporation at Companies House does not automatically register your company for Corporation Tax. The clock starts when the company begins trading or becomes active in any way that suggests it is carrying on business. HMRC defines this broadly and expects registration soon after activity begins.
For most new limited companies the trigger is the first commercial transaction, such as opening a business bank account that receives funds, signing a supplier contract, or making the first sale. Even preparatory work like buying domain names or incurring setup costs can count if it demonstrates intent to trade. The safest approach is to assume the three-month window begins on the incorporation date unless you can clearly show the company remained dormant.
Step-by-step guide to registering with HMRC
Register online through the GOV.UK website using your Companies House reference and personal Government Gateway account. You will need the company’s registered office address, incorporation date, Standard Industrial Classification (SIC) codes, and details of the directors. The process usually takes less than 15 minutes if all information is to hand.
- Gather incorporation documents and director identification.
- Create or log into a Government Gateway account linked to the company.
- Complete the online Corporation Tax registration form.
- Submit and retain the confirmation reference number.
After submission HMRC will issue a Unique Taxpayer Reference (UTR) within 15 working days. Keep this number safe as it is required for all future tax correspondence and filings.
Required notifications after incorporation
Beyond Corporation Tax, new companies must notify HMRC if they take on employees. This is done through the PAYE registration process, usually at the same time or shortly after Corporation Tax registration. Even if you are the sole director and plan to pay yourself via dividends rather than salary, it is wise to understand the rules in case your plans change.
Companies House must also be kept informed of any changes to the registered office, directors, or persons with significant control. While these notifications are separate from HMRC, failing to keep records current can create complications when filing accounts or tax returns. Use the same timeline mindset: deal with changes promptly rather than letting them accumulate.
Understanding accounting periods for new companies
Your company’s first accounting period usually begins on the date of incorporation and ends on the anniversary of that date in the following year, or on an earlier date you choose for your year end. Most new founders select a 31 March, 30 April or 31 December year end to align with common financial calendars and simplify bookkeeping.
The first Corporation Tax return (CT600) is due 12 months after the end of the accounting period, with payment of any tax due nine months and one day after the period ends. For a company incorporated in June 2024 with a 31 May 2025 year end, the return would be due by 31 May 2026 and any tax by 1 March 2026. These dates shift each year, so always verify the precise deadlines on GOV.UK once your accounting reference date is confirmed.
Initial tax obligations and record keeping
From the moment the company is active you must maintain accurate records of income, expenses, bank transactions, invoices and receipts. HMRC can request these records at any time, even for periods before the first full tax return is filed. Digital tools that export data in a compatible format reduce stress when preparing accounts.
New limited companies have no Corporation Tax to pay if they make no profit, but the return must still be filed on time. Late filing or late payment can result in automatic penalties that increase over time. Set calendar reminders for both the filing and payment deadlines as soon as your accounting period is set. Consider speaking to an accountant early to establish a simple system that grows with the business.
Common pitfalls and how to avoid them
Many founders assume that because turnover is low or non-existent in the first months there is nothing to do. This is incorrect. The obligation to register and file exists regardless of revenue levels. Another frequent mistake is using a personal address for all correspondence and then missing official HMRC letters.
Choose a professional registered office address if possible and monitor both postal and online messages through your Government Gateway account. Review your company’s status regularly on both Companies House and HMRC portals. Early-stage e-commerce sellers in particular can become distracted by platform fees, advertising campaigns and stock orders; scheduling a monthly admin hour helps keep compliance on track.
Making use of support available to new founders
Free resources on GOV.UK and HMRC’s website provide up-to-date guides, webinars and helplines. Many accelerators and incubators also offer basic guidance on these administrative steps. Loomworks in West Yorkshire, for example, provides selected early-stage founders with practical operator mentoring that can include help navigating initial company setup and compliance.
Take advantage of these resources before problems arise. A few hours spent understanding the system in the first month of trading prevents far greater costs and stress later. As your e-commerce business grows, the same disciplined approach to admin will support scaling without unwelcome surprises from tax authorities.
Frequently asked questions
Does my company need to register for Corporation Tax if it has no income yet?
Yes. Once your limited company starts any business activity you must register for Corporation Tax within three months. HMRC expects notification even if turnover is zero. The first return can show nil profits but must still be filed on time.
What is the deadline for the first Corporation Tax return?
The first return is due 12 months after the end of your company’s first accounting period. Payment of any tax is due nine months and one day after the accounting period ends. These deadlines vary by year end date so confirm them on GOV.UK once your accounting reference date is set.
Can I choose my own accounting year end date?
Yes. Most new companies align their year end with a calendar month end such as 31 March or 31 December. The first period runs from incorporation to the chosen year end date. Choose a date that simplifies bookkeeping and aligns with your e-commerce reporting cycles.
Do I need an accountant to register for Corporation Tax?
No. The online registration process is straightforward and can be completed by any director. However, many founders engage an accountant to set up record-keeping systems and ensure ongoing compliance as the business grows.
What happens if I miss the Corporation Tax registration deadline?
HMRC can issue penalties for late registration. The exact consequences change over time so check current rules on GOV.UK. Registering promptly and keeping good records is the simplest way to stay compliant from the start.
Related reading: When Should Your E-commerce Business Register for VAT?, How to File Self Assessment Tax Return as a Sole Trader, Which National Insurance Class Applies to Your Business Structure?. Browse all company admin & legal guides or apply to Loomworks.