Farra is a death administration assistant for UK families. Get step-by-step guidance for registering a death, applying for probate, notifying banks, and managing bereavement admin. From essential documents to practical checklists, Farra simplifies estate paperwork and funeral-related tasks so you can focus on what matters.
Need to apply for probate?
Answer 15 questions and we'll tell you exactly what to file, in what order — from £95.
Discovering you have missed an asset during probate is stressful, but it is far more common than most executors expect. The key is to act promptly and correctly. HMRC has a clear process for handling corrections — the C4 corrective account — and their approach to honest, timely disclosures is generally constructive. This guide explains exactly what to do, depending on how far through the process you are. For a broader look at what can go wrong during probate, see our guide to common probate mistakes executors make.
Before deciding what to do, it helps to understand why assets are missed in the first place. The most frequently overlooked assets are:
For a comprehensive list, see our guide to what counts as an asset for probate in the UK.
The right course of action depends on where you are in the probate process.
If you have submitted the IHT400 and PA1P but the Grant of Probate has not yet been issued, you can correct the application before the grant is released. Contact HMRC's Inheritance Tax team (0300 123 1072) to notify them of the additional asset and ask how to amend your IHT submission. Contact the Probate Registry to update the gross and net estate values on the PA1P if they have changed.
Acting at this stage costs you nothing — there are no penalties for correcting an error before the grant is issued.
Once the grant has been issued, the correct process is to submit a C4 corrective account to HMRC. The C4 is a straightforward form that allows you to:
The C4 must be signed by the executor(s) and sent to HMRC Inheritance Tax. HMRC will issue a revised calculation showing any additional IHT due, together with any interest that has accrued. You then pay the balance to settle the account.
Submitting a C4 corrective account does not trigger an investigation and is not an admission that you made a deliberate error. HMRC processes thousands of C4s every year. It is simply the standard mechanism for updating the IHT record during estate administration. Estates are complex, and corrections are expected.
Whether the missed asset results in additional IHT depends on the estate's position relative to the nil-rate band.
IHT is due 6 months after the end of the month of death (the "due date"). Interest accrues on any unpaid IHT from that date at the late payment rate, which is currently approximately 7.75% per year (linked to the Bank of England base rate plus a margin).
This means that if you discover a missed asset a year after the due date, and the additional IHT on that asset is £10,000, you will owe approximately £10,775 in total — the tax plus roughly £775 in interest. The interest is not a penalty; it is simply the cost of the money being paid late.
For more detail on how IHT interest works, see our guide to probate delays and IHT interest.
If you have distributed the estate to beneficiaries and then discover a missed asset, the situation is more complicated — but still manageable. You have two issues to address simultaneously:
Recovering funds from beneficiaries who have already received more than their correct entitlement (because IHT was underpaid) is legally possible but practically difficult. In most cases, where the beneficiary is cooperative and the amount is modest, this can be resolved informally. If the beneficiary is uncooperative, you may need legal advice.
This is one of the strongest reasons not to distribute the estate too hastily. See our guide on executor personal liability in the UK for more on the risks of premature distribution.
For a genuinely missed asset — one you did not know about and could not reasonably have found — there is typically no penalty. HMRC's penalty regime applies to careless or deliberate errors, not to honest omissions that are corrected promptly.
Provided you come forward with a C4 corrective account before HMRC contacts you (unprompted disclosure), the minimum penalty for a careless error is 0%. HMRC can charge up to 30% for careless errors, but routinely reduces or waives penalties for executors who act in good faith. See our guide on the consequences of making a mistake on your probate application.
For executors still in the early stages of administration, a systematic asset search at the outset prevents most omissions:
No — you can complete and submit the C4 yourself. HMRC provides guidance notes with the form. However, if the missed asset significantly changes the IHT position, or if you are concerned about the interest and penalty implications, professional advice may be worthwhile before submitting.
If the original estate was a full IHT estate (IHT400 was submitted), you should submit a C4 even if the additional asset creates no further IHT liability — to keep HMRC's records accurate and to protect yourself as executor. If the estate was a non-IHT estate, check with HMRC whether a correction is required. In practice, HMRC is unlikely to require a C4 if the additional asset has no tax consequence.
Contact NS&I to claim the Premium Bond as executor, then submit a C4 to update the IHT400. If the additional value pushes the estate over the nil-rate band or increases the taxable estate, additional IHT and interest will be due. If the estate remains below the nil-rate band, there is no additional IHT — simply update the record.
There is no fixed deadline for submitting a C4, but interest accrues from the original IHT due date. The sooner you submit, the less interest you will pay. HMRC has 4 years from the date the original IHT account was delivered to open an enquiry for honest errors, so there is a window — but acting promptly is always better.
Yes, legally — if beneficiaries received more than they should have because the IHT bill was understated, they have received funds that should have been retained for HMRC. In practice, if a beneficiary cooperates, the recovery can be done informally. If they refuse, legal action may be required. This situation is best avoided by not distributing the estate before the IHT position is fully settled.
What to do if you make a mistake on your probate application or IHT400. HMRC penalty rules, the C4 corrective account, unprompted disclosure, and executor personal liability explained.
What triggers HMRC to investigate an inheritance tax return, how to present your IHT400 to minimise scrutiny, and why property valuation and gift declaration are the most important factors.
What happens if HMRC challenges your property valuation for probate. How the District Valuer Service works, how to negotiate, IHT and interest implications, and how to correct an error via the C4.
When executors face personal liability. Distributing before paying debts, Section 27 Gazette notices, and when to consider an executor's bond.
HMRC charges 8.75% interest on unpaid inheritance tax. Learn how to pay IHT before probate and avoid unnecessary interest charges.
Ready to apply for probate?
Answer 15 questions and we'll tell you exactly what to file, in what order, and what to do when it gets complicated.
Get started →Free to start · from £95