When families search for inheritance tax when second parent dies, they are often trying to understand whether tax becomes payable after the surviving parent passes away and whether any unused inheritance tax allowance from the first parent can still be claimed.
In the UK, the death of the second parent can be particularly important for Inheritance Tax (IHT) because unused tax-free allowances from a deceased spouse or civil partner can potentially transfer to the survivor’s estate.
For the 2026/27 tax year, the standard nil-rate band is £325,000, while the residence nil-rate band can provide an additional £175,000 where the qualifying conditions are satisfied. HMRC has confirmed that these thresholds are currently scheduled to remain at these levels until 5 April 2031.
Where both parents were married or in a civil partnership and the relevant allowances were completely unused on the first death, the second parent’s estate could therefore potentially have up to £1 million of combined tax-free allowances. However, the £1 million figure is not an automatic exemption for every family.
What Happens to Inheritance Tax When the Second Parent Dies?
When the second parent dies, their executors or personal representatives generally need to establish the value of the entire estate.
This can include:
- Property and land
- Money in bank and savings accounts
- Investments
- Business interests
- Personal possessions
- Certain lifetime gifts
- The deceased’s share of jointly owned assets
- Other assets that form part of the estate
Debts, eligible exemptions and applicable tax reliefs are then taken into account before the estate’s potential Inheritance Tax liability is established.
The standard Inheritance Tax rate is currently 40%, but it normally applies only to the taxable portion of the estate remaining after available allowances, exemptions and reliefs have been considered.
The important question following the second parent’s death is therefore not simply how much their estate is worth. Executors must also establish how much of the first parent’s Inheritance Tax allowances remain available to transfer.
Can the Second Parent Use the First Parent’s Inheritance Tax Allowance?
Potentially, yes.
Where the parents were married or registered civil partners, the unused percentage of the first person’s basic nil-rate band can generally be transferred to the surviving spouse or civil partner’s estate.
HMRC states that the basic threshold available following the death of the surviving spouse or civil partner can reach £650,000 where none of the first person’s £325,000 nil-rate band was used.
For example, suppose a husband dies and leaves his entire qualifying estate to his wife. Transfers between spouses are generally exempt from Inheritance Tax, so his basic nil-rate band may remain completely unused.
When the wife subsequently dies, her estate could potentially have:
| Allowance | Potential Amount |
| Second parent’s nil-rate band | £325,000 |
| Transferred unused nil-rate band | £325,000 |
| Potential combined basic threshold | £650,000 |
The actual calculation depends on what happened when the first parent died.
What if the First Parent Used Part of Their Allowance?
The surviving parent’s estate does not necessarily receive another £325,000 in full.
HMRC transfers the unused proportion of the first spouse or civil partner’s nil-rate band.
For example, if only 60% of the first parent’s nil-rate band remained unused, the second parent’s available nil-rate band could potentially be increased by 60% of the nil-rate band applying when the survivor dies.
This is why executors should locate paperwork relating to the first parent’s estate rather than automatically assuming that two £325,000 allowances are available.
Can the Second Parent’s Estate Really Be Worth £1 Million Before IHT?
In some circumstances, yes.
The often-mentioned £1 million Inheritance Tax allowance for married couples comes from combining the basic nil-rate bands with the residence nil-rate bands.
Potential maximum allowances could look like this:
| Inheritance Tax Allowance | Maximum Potential Amount |
| Second parent’s nil-rate band | £325,000 |
| First parent’s transferred nil-rate band | £325,000 |
| Second parent’s residence nil-rate band | £175,000 |
| First parent’s transferred residence nil-rate band | £175,000 |
| Potential total | £1,000,000 |
Government guidance confirms that qualifying estates of surviving spouses or civil partners can potentially pass on up to £1 million where both the basic and residence nil-rate bands remain available.
However, several conditions have to be met.
The £1 million figure should therefore be viewed as a potential maximum allowance, not a universal threshold applying whenever a second parent dies.
How Does the Residence Nil-Rate Band Work After the Second Parent Dies?
The residence nil-rate band, commonly called the RNRB, can increase the amount an estate may pass on before Inheritance Tax becomes payable.
It is currently worth up to £175,000 per person.
Broadly, it may apply where the deceased owned a qualifying home or share of a home and passes it to qualifying direct descendants, such as children or grandchildren.
Government guidance explains that an individual’s threshold can potentially increase from £325,000 to £500,000 when a qualifying home is passed to children or grandchildren and the other requirements are met.
An unused residence nil-rate band from the first spouse or civil partner can also potentially be transferred to the survivor.
Consequently, a qualifying married couple or civil partnership can potentially obtain up to £350,000 of combined residence nil-rate band on the second death.
Does the £1 Million Allowance Apply to Every Couple?
No.
One of the most common misunderstandings surrounding inheritance tax when the second parent dies is that every married couple automatically receives a £1 million tax-free threshold.
That is not how the rules work.
The maximum figure generally depends on several factors, including:
- Whether the parents were married or civil partners
- How much of the first parent’s allowances were previously used
- Whether there is a qualifying residence
- Who inherits the property
- The overall size of the estate
- Lifetime gifts made before death
- Whether any relevant exemptions or reliefs apply
The residence nil-rate band is also restricted for larger estates.
What Happens if the Estate Is Worth More Than £2 Million?
The residence nil-rate band begins to taper once the estate exceeds £2 million.
HMRC has confirmed that this £2 million taper threshold continues to apply alongside the £175,000 residence nil-rate band.
The RNRB is generally reduced by £1 for every £2 by which the estate exceeds the taper threshold.
Consequently, wealthy estates may receive only part of the residence nil-rate band or none of it at all.
The ordinary £325,000 nil-rate band operates separately from this residence nil-rate band taper.
Example of Inheritance Tax When the Second Parent Dies
Consider a simplified example.
A married couple owns a home and other assets. The father dies first and leaves everything to his wife.
Because transfers to a surviving spouse are generally exempt from Inheritance Tax, assume that none of his basic nil-rate band or residence nil-rate band is used.
Several years later, the mother dies with an estate valued at £1.2 million, including a qualifying home that passes to her children.
Assuming all conditions are met, her estate could potentially claim:
- £325,000 own nil-rate band
- £325,000 transferred nil-rate band
- £175,000 own residence nil-rate band
- £175,000 transferred residence nil-rate band
That produces a potential total allowance of £1 million.
The remaining £200,000 could then potentially fall within the taxable estate.
At the standard 40% rate, that would indicate a potential IHT liability of:
£200,000 × 40% = £80,000
This is deliberately simplified. Actual estates may involve debts, lifetime gifts, charitable legacies, trusts, business or agricultural assets and other issues that alter the final calculation.
What if the Parents Were Not Married?
This can make a major difference.
The transferable nil-rate band rules apply to spouses and civil partners. Simply living together or being the parents of the same children does not automatically create the same transferable Inheritance Tax allowances.
Government guidance confirms that transfers of unused thresholds concern surviving spouses and civil partners.
Therefore, two unmarried parents cannot normally assume that the unused nil-rate band of the first parent will be added to the estate of the second parent. This distinction can substantially affect the eventual Inheritance Tax position.
What Happens if the First Parent Left Money Directly to the Children?
Leaving assets to children on the first death may use some or all of the first parent’s nil-rate band.
Suppose the first parent left £200,000 directly to children rather than leaving everything to their spouse.
That transaction could use part of the first parent’s available nil-rate band. The percentage remaining unused could then potentially be transferred to the surviving spouse.
The executors dealing with the second parent’s estate therefore need to establish what happened on the first death, including:
- The value of the first estate
- Who inherited the assets
- Whether spouse exemption applied
- Whether the nil-rate band was used
- Whether the residence nil-rate band was used
- Whether substantial lifetime gifts were made
Keeping the first parent’s probate and estate records can make this process considerably easier.
Do Gifts Made by the Second Parent Affect Inheritance Tax?
They can.
Executors need to consider relevant gifts made before death when calculating the estate’s Inheritance Tax position.
HMRC states that gifts made within the seven years before death may need to be considered, subject to the various exemptions and rules applying to lifetime gifts.
For example, there is generally a £3,000 annual gift exemption, while separate rules exist for wedding gifts, small gifts and qualifying regular gifts made from income.
Simply transferring ownership of assets shortly before death does not therefore guarantee that those assets escape Inheritance Tax.
How Do Executors Claim the First Parent’s Unused Allowance?
Transferable allowances may need to be formally claimed when dealing with the surviving parent’s estate.
For the basic nil-rate band, HMRC provides form IHT402, which is used with form IHT400 to claim an unused threshold from a previously deceased spouse or civil partner.
The transferable residence nil-rate band can be claimed through the relevant HMRC residence nil-rate band forms, including IHT436 where applicable.
Executors may need information relating to the first death, such as the previous will, probate documents and details of the earlier estate.
When Must Inheritance Tax Be Paid After the Second Parent Dies?
Inheritance Tax is normally paid from the deceased person’s estate rather than being an ordinary personal tax bill handed directly to the children.
HMRC states that Inheritance Tax must generally be paid by the end of the sixth month after the month in which the person died. Interest can become payable after the deadline.
A payment towards the Inheritance Tax bill is also normally required before a grant of representation can be obtained.
Special payment arrangements can apply to certain assets. For example, HMRC allows Inheritance Tax on qualifying assets that may take time to sell to be paid by annual instalments in some circumstances.
Does the House Automatically Have to Be Sold to Pay Inheritance Tax?
No.
Whether a property has to be sold depends on the estate’s circumstances, available cash and how the beneficiaries intend to deal with the property.
Some estates have sufficient savings or investments to meet their tax liability. Others may ultimately sell the home.
There are also circumstances in which eligible Inheritance Tax relating to property can be paid in instalments, although interest and specific HMRC rules may apply.
The existence of an IHT liability therefore does not by itself mean HMRC automatically takes or sells the family home.
Final Thoughts
Understanding inheritance tax when second parent dies requires looking at both deaths rather than considering the surviving parent’s estate in isolation.
Where the parents were married or civil partners, unused allowances from the first death can potentially increase the tax-free amount available on the second death.
The combined basic nil-rate band may reach £650,000, while qualifying estates that also receive the full residence nil-rate bands could potentially reach a total of £1 million.
That £1 million figure is not guaranteed. The first parent’s earlier estate, lifetime gifts, ownership of the family home, beneficiaries, estate value and the residence nil-rate band taper can all change the calculation.
For executors, one of the most useful steps is therefore to retain or locate the documents from the first parent’s estate. Those records can establish how much of the first parent’s allowances remains available when calculating the final Inheritance Tax position after the second parent’s death.
Frequently Asked Questions
How much can children inherit tax-free when the second parent dies?
There is no single allowance specifically given to the children. Instead, Inheritance Tax is calculated by reference to the deceased parent’s estate and its available exemptions and allowances.
A qualifying estate could potentially have allowances of up to £1 million where the second parent can use both spouses’ full nil-rate bands and residence nil-rate bands. Not every estate qualifies.
Is Inheritance Tax automatically due when the second parent dies?
No. It depends on the estate’s taxable value after available allowances, exemptions and reliefs have been considered.
Do you get two £325,000 allowances when the second parent dies?
Potentially. If the first spouse or civil partner did not use their nil-rate band, the survivor’s estate may be entitled to a combined basic nil-rate band of up to £650,000.
Can the £175,000 residence allowance also transfer?
Yes. An unused residence nil-rate band can potentially transfer between spouses or civil partners, subject to the qualifying rules.
What is the maximum inheritance tax allowance for a married couple?
Under the current thresholds, a qualifying estate could potentially benefit from £650,000 of combined basic nil-rate bands plus £350,000 of combined residence nil-rate bands, giving a maximum potential figure of £1 million.
What rate of Inheritance Tax is charged after allowances?
The standard rate is 40% on the taxable portion of an estate above its available thresholds.
Tax disclaimer: This article provides general information about UK Inheritance Tax and does not constitute personalised tax, financial or legal advice. Inheritance Tax can become complex where estates contain trusts, substantial lifetime gifts, businesses, agricultural property, overseas assets or estates above the residence nil-rate band taper threshold. Executors should use current HMRC guidance and consider professional advice where necessary.