We’ll walk you through what people mean by an “HMRC trust tax number” and why there are actually two possible references you might receive after registration.
After you register on the Trust Registration Service (TRS), HMRC issues either a Unique Reference Number (URN) for non-taxable trusts or a Unique Taxpayer Reference (UTR) for taxable trusts. The reference helps identify the arrangement in official correspondence.
This guide is for trustees and families in the UK who manage trusts as part of estate planning. We set clear expectations on timing: you get the reference only after TRS registration, not before.
We’ll keep the steps practical and jargon-light. You will learn how the reference fits into day-to-day administration, what to watch for with Government Gateway access and identity matching, and why it matters not to misplace the HMRC letter.
Key Takeaways
- Registration on TRS triggers an official reference from HMRC.
- There are two possible references: URN for non-taxable and UTR for taxable arrangements.
- Keep the letter safe — it’s needed for solicitors and accountants.
- Common hurdles: Government Gateway login and identity matching.
- Our guidance keeps steps simple so you can act with confidence.
What an HMRC trust tax number is and when you’ll receive it
Once the TRS submission is processed, you’ll receive a formal letter showing which identifier applies to your arrangement.
A URN identifies a non-taxable arrangement on the trust registration service. A UTR is a ten‑digit code issued when there is a tax liability and HMRC expects returns.
How the registration service supports anti‑money laundering checks
The TRS helps the authorities check who controls assets. Rules widened in recent years, so more trusts fall within the scope.
When you must register and remain registered
Registration is required where the criteria say so, and some existing trusts had historic deadlines to comply. Being trust registered is an ongoing duty.
| Identifier | Applied when | Main action once issued |
|---|---|---|
| URN | Arrangement not taxable | Keep the letter for records |
| UTR (10 digits) | Arrangement has tax liability | Use for returns and agent linking |
| TRS confirmation | After accepted submission | Update details if things change |
Plain reminder: registering is not a one‑off task. We advise keeping your record current and checking for any required register updates to avoid penalties.
What you need before you start trust registration on the TRS
Start by naming the lead trustee and collecting basic identity and trust facts. This helps you finish registration in one sitting.
Lead trustee role and access
The lead trustee is the only person who can claim and manage the online record. All trustees remain responsible for decisions, but the lead acts as HMRC’s main contact and controls the TRS entry.
Information to gather for people involved
Have to hand the personal details for trustees, settlors and beneficiaries. These include date of birth, nationality, residence and contact details.
Where possible, include a National Insurance number or passport details. If someone lacks capacity, you may need a Vulnerable Person Election (VPE1).
Core trust details you will be asked for
Prepare the trust name, date created and type — for example whether it is an express trust. You must also answer property questions.
Note the specific question about whether the trust acquired land or property since 6 October 2020. The TRS also asks if the arrangement is registered elsewhere in the EEA.
Government Gateway basics
Set up a Government Gateway account using an email, your name and a password. Choose an Organisation account when acting for a trust.
That choice helps link the gateway to the TRS and avoids access issues when you later add agents or accountants. For sign-in help see our guidance on registering as a trustee or read our advice for agents at registering as an agent.
| Item | Why it matters | Examples |
|---|---|---|
| Lead trustee details | Main contact and online manager | Name, email, organisation account |
| Personal details | Identity checks and matching | DOB, NI or passport, address |
| Trust facts | Determines registration route | Name, date created, express trust, property held |
| Mental capacity note | Protects vulnerable beneficiaries | VPE1 form if someone lacks capacity |
How to get your hmrc trust tax number through the Trust Registration Service
Registering your arrangement on the GOV.UK Trust Registration Service starts a short, clear process that ends with an official letter to the lead contact.
Registering the trust on GOV.UK via the Trust Registration Service
Sign in with a Government Gateway organisation account. Follow the on‑page questions about the lead trustee, people involved and core trust facts. Save a copy of your submission for your records; it helps if you need to check details later.
What happens after registration and how HMRC issues the URN or UTR letter
After you press submit, HMRC processes the entry and posts a letter to the lead trustee. The letter contains either a URN — 15 letters and digits, for non‑taxable arrangements — or a UTR — ten digits, for taxable arrangements. Keep the reference safe; it is the key identifier for future correspondence.
Keeping your URN or UTR safe for future HMRC correspondence
Store the postal letter securely. Scan a copy and save it in a protected folder. Give your solicitor or adviser a copy so they can act without delay if you misplace the original.
For a wider guide on setting up and managing a UK arrangement, see Unlock the benefits of a UK.
How the lead trustee can claim and manage a trust already registered
Claiming a registered arrangement links the lead trustee to the existing record so they can update details and act for the trustees. Only the lead trustee may make this claim on the TRS, so having the right documents ready saves time and stress.
Accessing the correct GOV.UK page and signing in
Go to the “Manage your trust’s details” page on GOV.UK and choose to sign in with a Government Gateway organisation account. Use the gateway credentials created when the trust was first set up.
Passing the TRS security checks with matching identity details
Have the lead trustee’s full name, date of birth and National Insurance ready. TRS requires exact matches to the record. You will also need one other person’s details linked to the arrangement for verification.
Linking the URN/UTR and confirming an agent
Enter the URN/UTR from the official letter to link the record. The page asks if an agent (for example, a solicitor or accountant) will manage the register. Confirming an agent lets them act on your behalf once properly authorised.
Common lockouts and errors to avoid
Check spellings, historic addresses and any old personal data before you submit. Three failed identity attempts locks access for 30 minutes, so move slowly and double‑check entries.
| Step | What to have ready | Why it matters |
|---|---|---|
| Sign in | Government Gateway organisation account | Connects you to the TRS manage page |
| Identity checks | Name, DOB, National Insurance, plus one other person | Ensures the lead trustee is correctly matched |
| Link record | URN or UTR from the letter | Links the online record to your claim |
| Agent confirmation | Agent details if used | Allows authorised advisers to work on the record |
If you need extra help, see our short guide for trustees on how to claim and manage a record at register a trust as a trustee. Keep calm, prepare the details, and you will avoid the common pitfalls.
What to do after you have the number: updates, annual declarations and closing the trust
Receiving the official reference starts a practical set of duties: updates, annual checks and, when needed, closure.
Keep details current within 90 days
Act within 90 days of any change to trustees, beneficiaries, addresses or property. Examples include a new trustee, a beneficiary reaching an entitlement, or a change of lead contact.
Make the update on the TRS service and save a confirmation. That short record prevents confusion later and helps any adviser who needs access.
Annual declarations and the tax year
For arrangements with a UTR, an annual declaration is required by 31 January after the tax year ends. The “tax year” runs from 6 April to 5 April.
Even if nothing changed, submit the declaration for that year. It keeps the register compliant and avoids query letters.
Penalties for failing to update
Deliberate failure to keep the register up to date can lead to penalties. In clear terms, fines can reach up to £5,000 where breaches are intentional.
When you may also need a tax return
Some arrangements must file a Self Assessment Trust and Estate Tax Return (SA900) as well as the TRS declaration. Check whether you also need to submit a return in the same year.
Closing and deregistering once assets are distributed
To close the record, the lead person selects “Close the trust”, enters the closure date (when trust assets were appointed out) and confirms details are accurate.
Save or print the deregistration declaration and share it with your solicitor or adviser for future queries.
Need a refresher on how to manage the register online? See the official guidance to manage your trusts registration service for step‑by‑step help: manage your trusts registration service.
Conclusion
As a final note, small habits—accurate entries, safe storage and prompt updates—prevent most delays.
We recap the journey: complete registration, receive the official reference, then claim and manage the record as the lead trustee. Keep copies of the letter, name lists and important dates in a secure place.
Key habits to follow are simple. Enter clear information, save scans, and act within the 90‑day window for changes. These steps keep families out of trouble and make administration straightforward.
If you need help, use official guidance or contact the helpline on 0300 123 1072 (from abroad +44 300 123 1072). You can also write to Trusts, BX9 1EL, or use the online assistant and apps.
Need a fuller walkthrough? See our step‑by‑step guide to registering a trust in Britain to move forward with confidence.