Corporation Tax registration for a new limited company: CT41G

Field note, 19 October 2026: I spent the morning rereading HMRC's pages on corporation tax registration for a new limited company, and the detail I keep coming back to is an address rather than a form.

Every letter in this process goes to the UK registered office. For a director who lives abroad, that one fact can decide whether the first deadline is met or missed while an envelope sits unopened at a UK address.

The online step is short, but it cannot start without a UTR. HMRC's guide on finding the number is plain about where it goes: “HMRC will send it to the business address that’s registered with Companies House.”

The same guide then adds the two sentences that matter most to an owner in another country: “You’ll usually get your UTR by post around 15 days after you register. It takes longer if you live overseas.”

I read those lines as the whole problem in miniature.

So the practical answer comes before any of the detail, and it is about people rather than forms. Before the company does any business, make sure someone at the registered office opens the post and passes on anything from HMRC within days.

When does a new limited company have to register for Corporation Tax?

The duty starts when the company starts to do business, not on the day Companies House forms it. HMRC's page on adding the service says so directly: “You should add Corporation Tax services to your account when you start to do business.”

That page names buying, selling, advertising, renting a property and employing someone.

I do not treat that list as complete. HMRC's separate guidance on trading and non-trading also counts providing services, earning interest, managing investments and receiving any other income as being active for Corporation Tax.

The legal deadline sits in section 55 of the Finance Act 2004. As I read it, the company must give notice of the start of its first accounting period, and the Act says that notice “must be given not later than three months after the beginning of the accounting period”. It must also be in writing.

Why does the clock follow trading rather than incorporation? HMRC's COTAX manual, the internal guide its own staff work from, gives the answer in one line: “many companies do not start to trade immediately and do not have all the necessary information at the time of registration”.

Preparation alone does not start the clock for HMRC. Its trading guidance puts writing a business plan or negotiating contracts on the pre-trading side of the line, along with costs incurred while a founder decides whether to start a business at all.

Take a hypothetical company formed in March whose director signs a first client contract and sends a first invoice in June.

On HMRC's rules its first accounting period would begin in June. The three-month notice window would run from June.

Of all the dates in the process, I pin down the start of business first, because every later deadline is counted from it.

What is the HMRC CT41G letter and where does it go?

The HMRC CT41G is the letter that carries the company's UTR. It is posted to the registered office soon after incorporation.

I went looking for the form in HMRC's COTAX manual and found it in a short table of new-company forms. The table names it the Corporation Tax information form for new companies. A neighbouring row notes that another form, the CT610 on important dates, stopped being issued in September 2016.

A second manual page says COTAX issues a CT41G to newly incorporated companies when they are set up on its system. Nobody has to ask for it.

HMRC also keeps an example copy in the manual's attachments. It is stamped as an example and carries the version code 02/22.

It is the closest thing to the real envelope a director will open, so I read it twice. Its first line explains how HMRC learns the company exists at all: “Companies House has informed us about the formation of your new company.”

Then comes the duty, stated in HMRC's own words. “You are required to send us certain information within 3 months of starting or restarting any business activity”, the letter says, before naming trading, providing services and earning interest as ways of starting.

Next to the UTR sits a three-digit tax office number. According to the example, the online registration service prompts for that number, so I would keep the paper copy even after the UTR has reached an email.

The letter closes with a line on HMRC's own limits. It says HMRC cannot give advice or help with the company accounts, and it suggests a qualified accountant where one is needed.

What can a director do about a UTR letter delay?

A UTR letter delay has one official fix, and that fix sends a second letter to the same registered office.

I note that the GOV.UK page for adding Corporation Tax sets the trigger at fifteen working days after registration. After that, a company with no UTR can request it online.

The request service is exact about the destination. Its start page says HMRC posts the copy to the registered address shown at Companies House, and gives its own explanation: “It’s sent by post to keep your details secure.”

Recently incorporated companies sit on the service's refusal list. The note beside them says their UTR should arrive at the registered address soon.

Calling HMRC does not shortcut the wait for a UTR. Its page for general Corporation Tax enquiries says the reference appears on all HMRC letters, then sets the rule for call handlers: “Our advisers cannot give you this reference over the phone.”

For a director abroad, part of any wait can be the distance between a UK letterbox and the person who needs the number.

Whoever holds the registered office address receives the CT41G. Somebody there has to open it, scan it and send it on. I would name that person before the company trades.

On a new company, the first thing I check is the registered office on the public register. HMRC's page asks for the same check before Corporation Tax is set up, and its explanation is short: “This is where all letters are sent.”

If the address is wrong, I would correct it through Companies House, not HMRC.

Appointing an accountant as agent may not move the post either. HMRC's guide on authorising someone says correspondence goes to the agent for Self Assessment, and for everything else it adds: “Otherwise, HMRC will continue to write to you.”

How does corporation tax registration for a new limited company work online?

Companies that register with Companies House online are usually set up for Corporation Tax at the same time, unless they are dormant.

I count four groups that need the separate enrolment step. HMRC lists companies registered by post, through an agent, through third-party software, or online without activating a business tax account.

I flag one detail here: the account needs its own Government Gateway sign-in. The Companies House registration page says a user ID and password are created for the company at registration, and it warns that a personal Gateway ID cannot be used.

To add the service, HMRC asks for the company registration number, the date business started, the date the first accounts run to and the UTR.

I give the start date the same care as the UTR. HMRC says the first accounting period will start from that date, so a wrong entry moves every deadline after it.

Only a few screens make up the online part: sign in, select the services that can be added, find Corporation Tax and choose to enrol. Then the post takes over again.

HMRC sends the activation code “within 10 days (21 days if you live abroad)”, together with instructions and the payment deadline, and says these are sent by post to the registered office address.

A director abroad can therefore be waiting on several letters at one UK address: the CT41G, the activation code and the letter confirming the accounting period dates.

I prefer the online route, but HMRC still accepts registration by letter. Its trading guidance lists the contents, from the company's name, number and accounting period start date to the nature of the business and the name and home address of each director.

Either a director or the company secretary must sign that letter, with a declaration that the information is correct and complete. It goes to Corporation Tax Services at the postcode-only address BX9 1AX.

Which deadlines follow once the company is registered?

Registration starts the company's accounting calendar, and HMRC's overview is blunt that no bill will arrive to prompt payment, because the company must work out, pay and report the tax itself.

An accounting period cannot be longer than twelve months. In the year the company is set up, the first one may differ from the financial year, and HMRC asks companies to tell it if the dates in its letter look wrong.

When I lay the dates side by side, payment comes first. For taxable profits up to £1.5 million, HMRC's payment guide sets the deadline at nine months and one day after the period ends.

The return is due twelve months after the period ends. A loss does not remove that duty.

Late returns are penalised on a fixed scale. HMRC's table starts at £200 one day after the deadline, adds another £200 at three months, and at six months moves to an estimated bill plus a penalty of 10% of the unpaid tax.

Back to the form for a moment, because one more deadline sits outside the registration pages. Schedule 18 to the Finance Act 1998 covers a company chargeable for a period that has received no notice to deliver a return.

Such a company must tell HMRC itself, and that notice “must be given within twelve months from the end of the accounting period”.

A lost CT41G pauses none of these dates.

What if the company is not trading yet?

A company that is formed but idle is usually dormant for Corporation Tax. HMRC's dormant company page lists a new limited company yet to start trading among its examples.

The example CT41G asks for word either way. It says a company that is dormant or not trading must inform HMRC at the earliest opportunity, preferably online, and warns that a company which stays silent will still be required to submit a return.

HMRC's trading guidance repeats the warning in almost the same words: a company that never told HMRC it was dormant must still submit a return, and a failure to file may lead to penalties against the company.

I see silence as the expensive choice here, even for a company with no income at all.

Once business begins, the dormant label falls away. The three-month notice then runs from the first day of activity, and HMRC's written-notice list even asks for the date the company first became obliged to operate PAYE.

What do HMRC's pages leave unclear for a director abroad?

No page I read gives a fixed time for the overseas wait, and two pages describe the normal wait differently.

The UTR guide says around fifteen days after registration. The page on adding the service uses fifteen working days before a copy can be requested.

I plan around the second figure, because fifteen working days is the point at which HMRC's own request service opens its door to a company still waiting for the letter.

I cannot tell from the UTR guide whether ‘overseas’ means the person or the address. A company's letter goes to its registered office. My guess is that the phrase was written with Self Assessment taxpayers in mind.

HMRC's example CT41G is a template marked for its manual. I am not sure the letters posted this month use exactly the same wording, and the manual's list of forms is silent on it.

The penalty position for a late section 55 notice is less clear than the deadline. The COTAX manual says companies could originally be charged a penalty for missing it, and then gives its staff this instruction: “Even if you think the information is incomplete, do not contact the company further.”

My reading is that this is a rule for HMRC's internal process, not permission to skip the notice. The Act still sets the three-month limit.

None of this replaces a check on a particular company, and an accountant who knows it can confirm the start date of business, the first accounting period and its tax residence before anything is filed.

What comes next once the UTR has arrived?

My view after a morning with these pages is that the weak point of corporation tax registration for a new limited company is the letterbox, not the online form.

As I map it, HMRC fixes the order of the steps. The CT41G with the UTR comes first, then enrolment with a start date, then the activation code by post, and last the letter with the accounting period dates.

Each of those steps waits on the registered office. So I treat a reliable scan of that post as the first task for any company run from abroad.

For the hypothetical June company, the notice would fall due in September. Its first return would be due twelve months after its first period ends, with the payment date about three months earlier.

What still bothers me is how much rests on one sentence of HMRC's UTR guide. It says the wait takes longer overseas, and none of the pages I read puts a number on longer.