A death disrupts everyday life. Funeral arrangements, paperwork, calls to banks: everything piles up. Meanwhile, a clock is ticking unseen. It marks the six-month deadline for paying Inheritance Tax (IHT) to HMRC.
Many beneficiaries assume they have months to settle the estate entirely before dealing with the tax bill. This is a common—and expensive—mistake. The deadline is not about dividing assets between heirs, which can take months or years. It is about submitting the IHT return to HMRC and paying the tax due.
The six-month deadline: what it covers (and what it does not)
The rule is straightforward on paper: beneficiaries have six months from the date of death to pay Inheritance Tax. After that deadline, HMRC treats the payment as late, with immediate financial consequences.
What confuses many families is the confusion between this tax obligation and the distribution of assets. A solicitor or probate specialist may take months to value an illiquid estate, locate assets, or unlock a complex succession among several beneficiaries. This work of dividing the estate is not subject to any strict legal deadline. However, the IHT payment must be made within six months, even if the final distribution has not been completed.
Who must pay Inheritance Tax and what is the exact deadline?
All beneficiaries are in principle liable for Inheritance Tax, although some smaller estates may be exempt. An exemption applies when the net value of the estate is below the nil-rate band (currently £325,000 per person), or where the estate qualifies for other reliefs such as spouse exemption or charitable giving.
In practice, the IHT return (form IHT400) is often submitted by the solicitor handling the probate, but beneficiaries can also submit it directly to HMRC. The starting point of the deadline is always the date of death, not the date beneficiaries learn of the death or the date a solicitor is instructed.
The financial cost of missing the deadline: interest and penalties mount quickly
Interest on late payment and penalties
After the six-month deadline has passed, HMRC automatically charges interest on any unpaid IHT. Interest runs from the day after the deadline and accrues on a daily basis. Late payment penalties may also apply depending on how long the payment remains outstanding. These are not symbolic costs: they are calculated on the total amount of IHT due, not a fixed sum. The larger the estate, the faster the bill grows.
A worked example of the cost of delay
Suppose an estate owes £15,000 in Inheritance Tax. A delay of eight months triggers interest from the deadline onwards. If interest runs at a typical rate on unpaid tax, even a two-month delay beyond the deadline can add several hundred pounds. Longer delays compound this further, and penalties for persistent non-payment can be substantial. An eight-month delay could easily add £1,500 or more to the original bill, before any additional enforcement action by HMRC.
The trap of compounding delay
Unlike a fixed fine, interest on late payment accrues every day. An estate delayed six months beyond the deadline does not cost twice as much: it costs significantly more once interest has accumulated and penalties have been applied.
How to avoid penalties when meeting the deadline is difficult
A complex estate, property to value, a missing beneficiary: reasons for missing the deadline are common. Fortunately, solutions exist to reduce or avoid penalties.
Instalment arrangements to spread payment
When all assets have not yet been valued or sold, beneficiaries can request to pay IHT by instalments over a period of years, rather than as a lump sum at the six-month deadline. HMRC can grant instalment arrangements, particularly for estates that include land or buildings difficult to sell quickly. Interest is charged on the deferred amounts, but this keeps the immediate payment manageable.
Early communication with HMRC
Beneficiaries who cannot raise the funds to pay IHT by the deadline should contact HMRC as soon as possible to discuss options. A voluntary approach, before any formal enforcement action, can sometimes result in a more flexible arrangement. Waiting until a demand is issued tends to leave less room for negotiation.
| Situation | Consequence |
|---|---|
| IHT paid within six months of death | No penalty or interest |
| Late payment after six months | Interest accrues daily from the deadline |
| Persistent non-payment after formal demand | Additional penalties and enforcement action |
If the deadline has already passed: what to do now and what options remain
If the deadline has already been missed, the worst option is to do nothing. The IHT return should be submitted to HMRC as soon as possible, even if incomplete, and steps should be taken to regularise the position. Voluntary disclosure, before HMRC takes formal action, often allows for a better outcome.
Be aware that HMRC cannot pursue IHT assessments indefinitely. There are limits to how far back HMRC can go to recover unpaid tax, which provides some reassurance if an estate has been overlooked for some years. However, this is not a reason to delay further. The longer an IHT debt remains unpaid, the larger it becomes through accruing interest.
In all cases, instructing a solicitor or probate specialist remains the best protection against this situation. They understand the deadlines, know when to request instalment arrangements, and can anticipate difficulties with illiquid assets or dispersed beneficiaries. The cost of their help is often far less than the cost of interest and penalties on a substantial IHT bill.
