Form IHT421 Probate Summary: Which Figures the Probate Registry Actually Needs
Form IHT421 is the short "probate summary" HMRC stamps and sends to the probate registry to confirm an estate's value once Inheritance Tax has been settled. It carries only four headline figures — the gross and net estate for probate, and the gross and net estate for Inheritance Tax — and those numbers are usually different. Getting them to match your PA1P application is what keeps the grant moving.
What the IHT421 actually is — and how it differs from the IHT400
The IHT400 is the full Inheritance Tax account: dozens of pages, every asset, every debt, every gift, every relief, and up to 27 supplementary schedules (IHT401 through IHT436). It is how HMRC works out whether tax is due and how much.
The IHT421 "Probate Summary" is something different and far shorter. It does not calculate tax. It is a one-page certificate whose only job is to tell the probate registry the values it needs to issue the grant. Where the IHT400 is the workings, the IHT421 is the answer that gets passed across to the court. HMRC's own guidance confirms you "must enclose an IHT421 or C1 if you're applying for probate or confirmation" alongside the IHT400 (gov.uk — IHT400 Inheritance Tax account).
Since 18 January 2024, the version of IHT421 published on gov.uk is labelled for applicants seeking a grant of representation in Northern Ireland only. In England and Wales, the probate summary is normally handled within the IHT400 process and HMRC issues a unique probate reference code (rather than returning a stamped paper form to you). In Scotland, the equivalent is form C1, used for confirmation. Always check which version applies to the jurisdiction you are applying in before you print anything (gov.uk — IHT421).
Probate vs Inheritance Tax: why there are two sets of figures
The single most common point of confusion is why the form asks for the estate value twice. It is because "the estate" means two different things to two different audiences:
- For probate — only the assets the personal representatives can actually deal with under the grant. This generally excludes assets that pass outside the will, such as property held as joint tenants (which passes automatically by survivorship) and most nominated or trust assets.
- For Inheritance Tax — a wider figure that includes the deceased's share of jointly held property, certain gifts made in the seven years before death, and assets in some trusts, because HMRC taxes the whole taxable estate, not just the probate estate.
This is why the "for IHT" figures are usually higher than the "for probate" figures. They are not errors — they are answering two different legal questions.
The four figures the probate registry needs
Stripped to essentials, the probate summary asks you to certify four numbers:
| Figure | What it means | Typically |
|---|---|---|
| Gross value of estate for probate | Total assets the PRs can administer, before deducting debts. Excludes survivorship/joint-tenant assets. | Lower |
| Net value of estate for probate | The probate gross figure minus debts and funeral expenses. This is the number the registry records on the grant. | Lower |
| Gross value of estate for Inheritance Tax | The full taxable estate including the deceased's share of joint property and relevant lifetime gifts. | Higher |
| Net value of estate for Inheritance Tax | The IHT gross figure minus allowable deductions and exemptions, used to assess tax. | Higher |
The exact box numbers carry across directly from your IHT400 calculation, so the discipline is simply: finish the IHT400 first, then transcribe its summary totals onto the IHT421 (or read off the values the digital service generates).
Worked example: Margaret's estate
Margaret Whitfield, a widow, dies in Leeds on 12 February 2026, leaving a valid will. Her son George is the executor. Her assets and liabilities:
- Sole-name home: £420,000
- Bank and savings accounts (sole name): £95,000
- ISA (sole name): £30,000
- Half-share of a buy-to-let flat held with her sister as joint tenants; whole flat worth £280,000, so her share is £140,000 — this passes by survivorship to the sister, outside the will
- Funeral costs and outstanding utility bills (debts): £12,000
- No taxable lifetime gifts in the seven years before death
Step 1 — Gross estate for probate. Only the sole-name assets George can administer: £420,000 + £95,000 + £30,000 = £545,000. The joint-tenant flat is excluded because it never enters the probate estate.
Step 2 — Net estate for probate. £545,000 − £12,000 debts = £533,000. This is the figure the registry records.
Step 3 — Gross estate for Inheritance Tax. Now add back the survivorship asset, because HMRC taxes it: £545,000 + £140,000 = £685,000.
Step 4 — Net estate for Inheritance Tax. £685,000 − £12,000 debts = £673,000.
Is any tax due? Margaret is a widow. She has her own nil-rate band of £325,000, plus she can claim her late husband's unused band (a 100% transfer, another £325,000), and because she leaves her home to her son she can use the residence nil-rate band, lifting the household threshold toward £500,000 per spouse. With both transferred allowances available, her combined threshold comfortably exceeds the £673,000 net IHT figure, so no Inheritance Tax is payable — but George still completes the IHT400 and obtains the probate reference because the estate is above the excepted-estate reporting limits and includes a transferred nil-rate band claim.
The result George carries to the registry:
| Box | Margaret's figure |
|---|---|
| Gross value of estate for probate | £545,000 |
| Net value of estate for probate | £533,000 |
| Gross value of estate for Inheritance Tax | £685,000 |
| Net value of estate for Inheritance Tax | £673,000 |
Notice all four numbers differ, and that the "for probate" pair is exactly £140,000 lower than the "for IHT" pair — precisely the survivorship flat. That £140,000 gap is the whole reason two columns exist.
The standard nil-rate band is £325,000 and the standard Inheritance Tax rate is 40%, charged only on the part of the estate above the threshold. Leaving a home to children or grandchildren can raise the threshold to £500,000 via the residence nil-rate band, which tapers away for estates worth more than £2 million. Source: gov.uk — Inheritance Tax and gov.uk — passing on your home. Confirm current-year figures before filing, as thresholds are set by HM Treasury and can change at a Budget.
How HMRC stamps and returns the IHT421
The mechanics changed materially in recent years, and it matters because it affects what you, the applicant, actually have to do.
Historically, you sent the IHT400 with the IHT421 to HMRC; HMRC checked the account, stamped the IHT421 to confirm the values, and returned it to you so you could file it with the probate registry. Since 1 June 2020, HMRC stopped returning completed forms to applicants and instead sends the stamped probate summary directly to HM Courts & Tribunals Service (HMCTS) Probate (gov.uk — IHT421). In practice this means:
- You no longer wait for a stamped paper form to land back on your doormat.
- HMRC routes the confirmation to the registry, and provides you a unique probate reference code to enter on your probate application instead.
- You should allow HMRC processing time before applying — HMRC asks that you wait around 20 working days after sending the IHT400 before you submit the probate application, so the values can reach the registry first.
The digital service — and when paper IHT421 is still required
For most England-and-Wales estates, the Inheritance Tax process now runs through HMRC's online service. The system captures the same figures and generates the probate reference code that links your account to the grant application, removing the need for a separate stamped paper IHT421 in the standard case.
A paper IHT421 (or its jurisdictional equivalent) is still required in situations such as:
- Applying for a grant of representation in Northern Ireland, where the current published IHT421 is specifically intended (per the January 2024 version note).
- Scottish confirmation, which uses form C1 rather than IHT421.
- Cases HMRC directs to paper, or where the online service cannot be used for that estate type.
Do not download and print an IHT421 by reflex. First confirm your jurisdiction and whether your estate is being handled through the digital IHT service. Using the Northern Ireland form for an England-and-Wales estate, or filing a paper IHT421 when a reference code was already issued, is a common cause of stops and queries.
Matching the IHT421 figures to your PA1P
If you apply for probate by post with a will, you use form PA1P. The figures you enter there must reconcile with what HMRC has on file. Since January 2024, the PA1P guidance explicitly includes questions about the letter from HMRC containing your unique probate code, which is the link between the tax process and the court application (gov.uk — PA1P).
Practical reconciliation checklist:
- Net estate for probate on the PA1P should equal the net-for-probate figure from your IHT400/IHT421 (Margaret: £533,000).
- Gross estate for probate should match the gross-for-probate figure (Margaret: £545,000).
- Enter the HMRC unique probate reference code exactly as issued — a mistyped code is one of the most frequent reasons a registry pauses the application.
- Wait until HMRC has had its processing window (around 20 working days) before submitting, so the registry already holds the values when your PA1P arrives.
If the probate figures on the PA1P do not match what HMRC sent across, the registry will query it — and a query at this stage typically adds weeks. The fix is almost always to keep one source of truth: complete the IHT400 first, read the four summary figures off it, and use those identical numbers everywhere.
- The IHT421 is a short probate summary — it reports values to the registry, it does not calculate tax. The IHT400 does the calculation.
- It carries four figures: gross and net for probate, gross and net for Inheritance Tax. The IHT figures are usually higher because they include survivorship/joint assets and certain gifts.
- Since 1 June 2020, HMRC sends the stamped summary directly to HMCTS Probate and gives you a unique probate reference code instead of returning paper.
- For most England-and-Wales estates the process is digital; a paper IHT421 is still used for Northern Ireland, while Scotland uses C1.
- Your PA1P figures and reference code must match what HMRC holds — reconcile before you submit, and allow HMRC's ~20 working day window first.
- Verified: nil-rate band £325,000, IHT rate 40%, threshold up to £500,000 with the residence nil-rate band (tapering above £2m).
Frequently asked questions
Is the IHT421 the same as the IHT400?
No. The IHT400 is the full Inheritance Tax account with up to 27 supplementary schedules and is where tax is calculated. The IHT421 "Probate Summary" is a short certificate that reports the resulting estate values to the probate registry. You normally enclose the IHT421 (or C1 in Scotland) with the IHT400 when applying for probate.
Why are the "for probate" and "for Inheritance Tax" figures different?
They answer different questions. The probate figures cover only the assets the personal representatives can administer under the grant, which excludes assets passing by survivorship (joint tenancies) or outside the will. The Inheritance Tax figures are wider, including the deceased's share of joint property and certain lifetime gifts, because HMRC taxes the whole taxable estate. The IHT figures are usually higher.
Will HMRC post the stamped IHT421 back to me?
Not since 1 June 2020. HMRC stopped returning completed forms and now sends the probate summary directly to HMCTS Probate, providing you with a unique probate reference code to use on your application instead. You should allow around 20 working days for HMRC to process before applying.
Do I still need a paper IHT421 in England and Wales?
Usually not. Most England-and-Wales estates run through HMRC's online Inheritance Tax service, which generates the reference code that links to your probate application. The current published paper IHT421 is intended for Northern Ireland grants of representation (per the January 2024 version note), and Scotland uses form C1. Check your jurisdiction before printing anything.
How do I match my IHT421 figures to the PA1P?
Use one source of truth. Complete the IHT400 first, read off the gross and net probate values, and enter those identical numbers on the PA1P. Then enter the unique probate reference code from HMRC's letter exactly as issued. Mismatched figures or a mistyped code are common reasons a registry pauses the application.
What if no Inheritance Tax is due — do I still file these forms?
Possibly. If the estate qualifies as an excepted estate you may not need the full IHT400, but you still report an estimated value to apply for probate. If you are claiming a transferred nil-rate band or the estate is above the excepted-estate limits, the IHT400 route (and its probate summary) applies even when no tax is ultimately payable.
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