How to apply for an Inheritance Tax reference number using IHT422
Before you can pay Inheritance Tax — or confirm there is none to pay — you need an IHT reference number from HMRC.
IHT422 is the form that requests it.
It takes 10 minutes to complete, and HMRC says to apply at least 3 weeks before you need to make a payment — which means it should be one of the very first steps the executor takes.
This walkthrough explains what information the form requires, how to apply online rather than by post, and where IHT422 fits in the estate administration sequence.
✓ Official source checked 2 September 2026 · GOV.UK last revised this form 5 June 2026IHT422 on GOV.UK ↗
This walkthrough takes IHT422 field by field, in plain English. The form itself is short; the hard part is timing and sequence — getting the reference at least three weeks before you pay, and in the right order so probate does not stall.
The timing mistake that stalls probate
Applying too late is the usual cause.
Many executors assume they can apply for the reference at the same time as submitting IHT400 — but HMRC needs at least three weeks to issue the reference.
If you apply for probate without first obtaining an IHT reference and paying (or confirming no IHT is due), the probate application will stall.
The correct sequence is: apply for the IHT422 reference, then pay the Inheritance Tax (or confirm none is due), then apply for probate.
The form, in summary
The IHT422 form, in summary.
Valoren
IHT422·2 pages·14 fields guided
With Valoren5 minutes
Without Valoren10 minutes
to complete; allow 3+ weeks for HMRC to issue the reference
An Inheritance Tax (IHT) reference number is a unique identifier issued by HMRC that is required before any payment of Inheritance Tax can be made — including payments via the Direct Payment Scheme (IHT423).
Without a reference, HMRC cannot match incoming payments to the correct estate.
The reference must be applied for at least 3 weeks before you intend to pay IHT.
Even if no IHT is due, some estates still need to file IHT400 and therefore still need a reference.
·Who Files — The executor (if there is a will) or the administrator (if there is no will)
·2 pages · 14 fields guided
·Draws from your Estate File — Civil Dossier, People, Authority & Contacts, Death & Estate Activation
Section01
§11
Section 1
When you need an IHT reference — and when you do not
Not every estate requires an IHT reference.
You only need one if you need to pay IHT or if you are required to submit a full IHT400 account. Most smaller, simpler estates use the excepted estate route and never file an IHT400 at all.
01
Estates that need an IHT reference
You need an IHT422 reference if: the estate is liable to Inheritance Tax (i.e. the total estate value exceeds the available nil rate band and any other exemptions); or if you are required to submit a full IHT400 even though no IHT is due (for example, if the estate exceeds £1 million, or if the deceased lived outside the UK, or if certain assets are being claimed for business or agricultural relief).
02
Excepted estates — no reference needed
If the estate qualifies as an 'excepted estate' under the Inheritance Tax (Delivery of Accounts) (Excepted Estates) Regulations 2024, you do not need to file an IHT400 and therefore do not need an IHT reference.
Excepted estates include: most estates below the nil rate band (£325,000, or £650,000 if a transferable NRB is available); qualifying low-value excepted estates; and some foreign domiciliary estates.
If you are using form PA1P or PA1A (probate application), the form asks whether the estate is excepted.
03
The 3-week lead time
HMRC states that IHT422 applications take at least 3 weeks to process.
During that time, you cannot make an IHT payment (there is nothing to reference the payment to), which means you cannot apply for probate.
Apply for IHT422 as early as possible — ideally within the first few weeks of the death, alongside gathering estate information.
04
If the tax is on a trust or a lifetime transfer — the form is IHT122, not this one
There are two different Inheritance Tax references, and this form is only one of them.
IHT422 is the reference for a death estate. It is the one you can apply for online, and it pairs with IHT400.
If Inheritance Tax is due instead because of a chargeable event — a charge arising on a trust or on a lifetime transfer — the form is IHT122. It cannot be submitted online: you complete it on screen, print it, and post it to HMRC. It pairs with IHT100, not IHT400.
Either way, apply at least 3 weeks before you intend to pay.
Not every estate requires an IHT reference.
HM Revenue & Customs (HMRC) · IHT422❦
Section02
§22
Section 2
Completing the IHT422 form
IHT422 is a short, two-page form. It asks for basic details about the deceased and about you as executor. Have the death certificate to hand before you start.
01
Part 1 — About the deceased
Full name of the deceased, date of birth, date of death, and the last address (the address at the date of death).
HMRC uses this to check existing HMRC records for the deceased — if they were Self Assessment registered, HMRC will link the IHT reference to their UTR.
Enter the date of death accurately: IHT deadlines are calculated from this date.
02
Part 2 — About you (the executor or administrator)
Your full name and address, your relationship to the deceased, and your contact details.
If there are multiple executors, the IHT reference can be applied for by any one of them — but the reference is issued in the name of the estate, not a particular executor.
All executors can use the same reference.
03
Applying online
HMRC now strongly prefers online applications for IHT422. Apply at gov.uk/inheritance-tax/overview.
Online applications are usually processed faster than postal ones (though the 3-week guide still applies).
The reference number will be sent by post to the executor's address — you cannot receive it by email.
04
What you receive
HMRC issues a letter confirming the IHT reference number.
Keep this letter — you will need the reference number every time you communicate with HMRC about the estate, and for the IHT423 Direct Payment Scheme form if you are paying IHT from the deceased's bank account.
IHT422 is a short, two-page form. It asks for basic details about the deceased and about you as executor. Have the death certificate to hand before you start.
HM Revenue & Customs (HMRC) · IHT422❦
Section03
§33
Section 3
Where IHT422 fits in the estate administration sequence
IHT422 is not the final step before probate — it is one of several things that need to happen in parallel. Understanding the sequence prevents costly delays.
01
The correct sequence
Step 1: Apply for IHT422 reference (do this early — it takes 3 weeks).
Step 2: Complete the full IHT400 and all relevant schedules (IHT401–IHT436).
Step 3: Pay the IHT due or arrange payment via the Direct Payment Scheme (IHT423).
Step 4: HMRC processes the IHT400 and payment, then sends a letter with a unique code and the estate values — allow 20 working days from submitting the IHT400.
Step 5: Apply for probate (PA1P or PA1A) using the unique code — since 17 January 2024 there is no stamped IHT421 to attach.
Step 6: HMRC reviews the IHT400 in parallel with probate — enquiries may follow after the grant is issued.
02
The 6-month payment deadline
IHT is due 6 months after the end of the month in which the death occurred.
For example, if the deceased died on 15 March 2025, IHT is due by 30 September 2025.
Interest accrues daily from that date at HMRC's late payment rate.
If the estate is complex and it is not possible to pay in full by the deadline, at least some IHT should be paid on account to limit the interest accruing.
03
Instalment option for certain assets
For property and unlisted shareholdings, IHT can sometimes be paid in 10 equal annual instalments rather than as a lump sum.
Interest still accrues on outstanding instalments.
This is useful when the estate is 'asset rich, cash poor' — a house forms the bulk of the estate and must be sold to pay IHT, but the sale will take months.
IHT422 is not the final step before probate — it is one of several things that need to happen in parallel. Understanding the sequence prevents costly delays.
HM Revenue & Customs (HMRC) · IHT422❦
Many people file IHT422 themselves — that is what this walkthrough is for. If the estate behind it has stopped being simple — inheritance tax to pay, a trust, foreign assets, a dispute — Signum, Valoren’s own specialist desk, can take it on, and we say so plainly: it starts with a free intake, and if you do not need us, we will tell you. Prefer an independent adviser? STEP and the Chartered Institute of Taxation both keep public member directories, and neither pays Valoren a referral fee.
FAQ
IHT422 questions, answered.
IHT422 is the form you use to apply to HMRC for an Inheritance Tax reference number.
You need that reference before you can pay any Inheritance Tax — including paying it from the deceased's bank account through the Direct Payment Scheme (IHT423).
Without a reference, HMRC cannot match your payment to the estate.
The executor, if there is a will, or the administrator, if there is no will.
Where there are several executors, any one of them can apply — the reference is issued in the name of the estate, not a particular person, so all the executors then use the same reference.
Apply at least three weeks before you intend to make any Inheritance Tax payment, because HMRC states the reference takes at least three weeks to issue.
Inheritance Tax itself is due six months after the end of the month in which the person died, so it is best to apply for the reference in the first few weeks, while you are still gathering estate information.
The wider account and reporting obligations sit under the Inheritance Tax Act 1984 (ss.216–217) and the Excepted Estates Regulations 2024 — check HMRC's guidance and consider professional advice for larger or cross-border estates.
No. HMRC does not charge a fee to issue an Inheritance Tax reference number.
The only cost is time — the three-week processing wait — which is why applying early matters more than anything else on this form.
Have the death certificate to hand for the deceased's full name, date of birth, date of death and last address, plus your own name, address, relationship to the deceased and contact details as the executor or administrator.
Confirming who holds authority to apply avoids duplicate applications where there are several executors.
Applying too late. Many executors try to get the reference at the same time as submitting IHT400, but HMRC needs at least three weeks to issue it — so the reference, not the account, should come first.
The correct sequence is: apply for the IHT422 reference, then pay the Inheritance Tax (or confirm none is due), then apply for probate.
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Where this fits
IHT422 is one form. The file behind it is the rest.
Forms are easier when the records are ready.
For IHT422, that means the deceased's death certificate (full name, date of birth, date of death and last address), the executor's or administrator's own name, address and contact details, and confirmation of who holds authority to apply — gathered early, because HMRC needs at least three weeks to issue the reference.
When you're ready — not before — our £179 Executor's First Hour walks you through registering the death, notifying banks and pensions, and getting probate started, in the right order. The free checklist above covers the essentials; this is for when you'd rather have a hand to hold. Executor's First Hour — £179 →
HM Revenue & Customs (HMRC)·14 fields·Free·5 minutes with Valoren
The return this attaches to
This is one schedule. It attaches to the IHT400 — the main Inheritance Tax account — which is where every schedule you complete comes together.
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