Do I Need to Tell HMRC I Have Set Up a Limited Company UK?
Yes, you still need to register for Corporation Tax within three months of starting to trade, even though Companies House has already told HMRC the company exists. This is one of those steps people assume is automatic, but it isn’t. This is where things get slightly confusing: Companies House sets up your company, but HMRC is a separate step.
Does Companies House tell HMRC about my new company?
Yes, Companies House automatically notifies HMRC when a new limited company is incorporated, but that notification does not register you for any taxes.
HMRC creates a record for your company and posts your Unique Taxpayer Reference (UTR) to your registered office, usually within a couple of weeks, though it often feels longer when you’re stuck waiting for it before you can do anything else. The UTR is the 10-digit number you will use to identify your company on every future tax form. That’s as far as HMRC takes it. You need to register for Corporation Tax yourself, and separately for PAYE, VAT, and Self-Assessment if they apply. This is where people often assume everything has already been handled. Each one has to be set up separately on the HMRC site.
What is the deadline to register for Corporation Tax?
You’re expected to register for Corporation Tax within three months of starting to trade, and it’s better to do it early rather than risk forgetting.
In practice, HMRC usually considers you to have started trading the moment money comes into the picture, your first invoice, a paid contract, or even buying stock to sell on. It does not mean buying stationery, registering a domain, or building a website while preparing to launch. If you’re still building things out, website, branding, testing the idea, HMRC usually won’t count that as trading yet. The line gets crossed once money starts moving. But as soon as you invoice or take payment, HMRC considers that trading. The penalty for late registration is up to £100, plus 10 per cent of any unpaid tax once your first Corporation Tax bill is due.
How do I register my new limited company for Corporation Tax?
You’ll do this through your business tax account on HMRC’s website, using your UTR, company number, and authentication code.
Sign in (or create) a Government Gateway account, then add Corporation Tax as a tax to your business tax account. HMRC will ask for your accounting reference date (usually the last day of the month you incorporated in, plus one year), the date you started trading, and the nature of your business. It’s a fairly quick form once you’ve got everything in front of you, most of the delay tends to be waiting for the UTR. HMRC then confirms your registration and tells you the date your first Corporation Tax payment is due, which is nine months and one day after the end of your first accounting period.
Do I also have to tell HMRC about PAYE, VAT and Self-Assessment?
In the first year, most directors only deal with Corporation Tax and possibly PAYE, VAT usually isn’t relevant unless turnover picks up quickly.
PAYE kicks in if you start paying yourself a salary above the Lower Earnings Limit. VAT is only compulsory once you pass £90,000 turnover, although some businesses register earlier if it helps with clients. Self-Assessment tends to follow when dividends or other untaxed income enter the picture. Each of these sits separately from Corporation Tax, which catches people out because it feels like it should all be one process. We have covered the full PAYE timing rules in When Do I Need to Register for PAYE as a UK Limited Company?
What documents do I need before I can register?
You need three things: your Certificate of Incorporation, your UTR letter from HMRC, and your Companies House authentication code.
The certificate is emailed by Companies House the moment your company is approved. The UTR is posted by HMRC within two weeks of incorporation. The authentication code is posted by Companies House within a few days. If something hasn’t turned up after about three weeks, it’s worth chasing, HMRC and Companies House letters do occasionally go missing or sit in post longer than expected. You can request a replacement copy of your UTR from HMRC online, or a copy of your authentication code from Companies House online, either will be posted out to the registered office address. Without all three, you’re basically stuck, you can’t properly register, file, or update anything until they’re in place.
Where does HMRC registration fit in the wider checklist?
Telling HMRC is just one of three early admin tasks most companies deal with straight after incorporation, the others being a bank account and getting a basic online presence set up. We have laid out the full deadline-ordered list in What to Do After Registering a Company in the UK: A Deadline-Ordered Checklist. The annual filings come later: the confirmation statement is due 12 months after incorporation, and your first set of accounts is due within 21 months.
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Frequently Asked Questions
Do I need to tell HMRC if my limited company is dormant?
Yes, you should tell HMRC your company is dormant so they do not expect a Corporation Tax return until you start trading.
How long after incorporation does HMRC send my UTR?
HMRC posts your UTR to your registered office within 14 days of Companies House notifying them of your new company.
Can I register for Corporation Tax before I start trading?
You can sign in to your business tax account at any time, but HMRC asks for the date you started trading, so most directors register on or just after that date.
Is HMRC registration the same as Companies House registration?
No, they are separate: Companies House registers your company’s legal existence, while HMRC registers it for the specific taxes it has to pay.
What happens if I never tell HMRC my company is trading?
HMRC will eventually find out, charge backdated Corporation Tax with interest and penalites, and add a late-registration penalty of up to £100 plus 10 per cent of unpaid tax.
