Inheritance Tax When Second Parent Dies – UK Rules and Thresholds

When the second parent dies, inheritance tax calculations change significantly because surviving spouses can claim unused allowances from their late partner. This means married couples and civil partners can effectively double their tax-free thresholds, potentially protecting up to £1 million from inheritance tax.

The rules around IHT on second death allow the surviving partner to transfer the deceased’s nil-rate band (NRB) and, where applicable, their residence nil-rate band (RNRB) to their own estate. These provisions, introduced through Finance Act 2008, mean that the second death is often where inheritance tax liability actually falls.

Understanding how these transfers work, and when they apply, can make a substantial difference to what heirs ultimately receive. The calculations depend on whether the first estate used any of its bands, the value of the surviving partner’s estate, and whether a qualifying residence passes to direct descendants.

Do You Pay Inheritance Tax When the Second Parent Dies?

Inheritance tax does not automatically apply when the second parent dies. Whether IHT is due depends entirely on the combined value of the surviving spouse’s estate and the transferable allowances they can claim from their late partner.

The first death of a spouse or civil partner is almost always exempt from IHT because of the spouse exemption. This exemption means that leaving everything to a surviving partner triggers no tax. Crucially, this preserved the deceased’s nil-rate band for potential transfer to the second death.

When the second parent dies, the executors calculate the estate’s net value, add any transferable bands from the first death, then apply inheritance tax only to the excess. If the total estate falls within the combined thresholds, no IHT is payable at all.

Key IHT Figures at a Glance

Key Insights on IHT for Couples

• Couples can potentially shield up to £1 million from inheritance tax by combining both partners’ NRB and RNRB allowances
• The nil-rate band has been frozen at £325,000 since 2009, with no increase expected before 2029/30
• The residence nil-rate band tapers for estates over £2 million, disappearing entirely at £2.35 million
• Claims for transferred bands must be made on form IHT402, typically within 24 months of the second death
• Keeping detailed records of the first death estate is essential for accurate claims
• Only the first two deaths in multiple marriage scenarios can boost transferable bands

Current IHT Thresholds for Couples

These figures are fixed according to the Autumn Budget 2024 announcement. The government confirmed that thresholds would remain frozen through the 2029/30 tax year, meaning no inflation-linked increases during this period.

How Is the Nil Rate Band Transferred on Second Death?

The nil-rate band transfer mechanism allows the surviving spouse to claim the unused portion of their late partner’s NRB. This works as a percentage calculation based on what was available at the first death, not what remained after gifts or other chargeable transfers.

If the first spouse died with an estate valued below £325,000, the full NRB would have been unused. This means the surviving partner could add 100% of the current £325,000 to their own threshold, effectively doubling their nil-rate band to £650,000.

The transfer is available regardless of when the first death occurred, provided the surviving partner was married or in a civil partnership at that time. Civil partners gained equivalent rights from December 2005 onwards.

Claiming the Transferred NRB

Executors use form IHT402 to claim the transferred nil-rate band when dealing with the second estate. The claim must be made to HMRC, and supporting documentation from the first death will be required.

The claim window generally extends to approximately 24 months from the end of the month in which the second spouse died. If this deadline is at risk, provisional claims can be submitted while figures are finalised.

What Is the Residence Nil Rate Band on Second Death?

The residence nil-rate band provides an additional £175,000 exemption for individuals passing a qualifying residence to direct descendants. On second death, this allowance can also be transferred if unused by the first spouse.

For the RNRB to apply, the property must be a qualifying residence and must pass to direct descendants, which includes children, grandchildren, and adopted, step, or in-law relationships. The definition of direct descendants specifically excludes siblings, nieces, or nephews.

The combined RNRB for couples can reach £350,000 if both partners qualify, taking the total tax-free residential allowance to £1 million when combined with the nil-rate bands.

How Does the Taper Work for Larger Estates?

The residence nil-rate band tapers for estates exceeding £2 million in value. For every £2 over this threshold, the RNRB reduces by £1. At £2.35 million, the residential allowance disappears entirely.

This taper applies to the estate value at second death, not the combined estates of both spouses. A surviving partner with a £2.2 million estate would see their RNRB reduced by £100,000, bringing it from £175,000 to £75,000.

How Much Inheritance Tax Is Due After Both Parents Die?

The inheritance tax calculation on the second death follows a clear sequence. First, the net value of the estate is established by taking all assets and subtracting debts, funeral expenses, and any reliefs. Then, transferable bands are added before applying the 40% rate to any excess.

Consider a scenario where the first spouse died in 2020 with a £200,000 estate. Their entire nil-rate band remained unused. When the surviving spouse dies in 2025 with a £900,000 estate including their home left to children, the calculation works as follows.

The survivor’s estate can claim the full transferred nil-rate band of £325,000 plus the transferred residence nil-rate band of £175,000, provided the home qualifies and passes to direct descendants. This creates a combined threshold of £1,000,000 against the £900,000 estate value.

In this example, no inheritance tax would be due because the estate value falls below the total available allowances. The £100,000 difference between the threshold and estate value represents unused capacity that cannot be carried forward.

Example: Estate Exceeding the Taper Threshold

If the surviving spouse’s estate totals £2.2 million with a qualifying residence passing to children, the residence nil-rate band tapers. The £200,000 excess above the £2 million threshold reduces the RNRB by £100,000.

The surviving partner would receive £325,000 from their own nil-rate band, £325,000 from the transferred nil-rate band, and £75,000 from the transferred residence nil-rate band (after taper), creating a total threshold of £725,000.

The taxable excess would be £2,200,000 minus £725,000, equalling £1,475,000. At the 40% rate, this would generate an IHT liability of £590,000 before considering any other reliefs or deductions.

This calculation demonstrates why understanding the taper rules is essential for estate planning, particularly for couples whose combined wealth places them above the £2 million threshold.

What Are the Current IHT Thresholds for Couples?

For the 2024/25 tax year and continuing through to 2029/30, the nil-rate band remains fixed at £325,000 per person. The residence nil-rate band sits at £175,000, subject to the taper rules outlined above.

A single person passing a qualifying residence to direct descendants can potentially shield £500,000 from inheritance tax. A married couple or civil partnership where both qualify and no IHT was paid on the first death can protect up to £1,000,000.

The Autumn Budget 2024 confirmed these figures would not change during this Parliament. The freezing of thresholds means more estates may fall into IHT liability over time as property values and savings grow.

Any amount above the combined thresholds is taxed at 40%, making effective estate planning increasingly valuable for couples with substantial assets.

Does Gifting Reduce Inheritance Tax on Second Death?

Lifetime gifting can reduce the estate subject to IHT on second death, but the rules are nuanced. Potentially Exempt Transfers (PETs) become fully exempt if the donor survives seven years from the date of the gift.

Gifts made within seven years of death may still attract IHT, though taper relief reduces the charge on a sliding scale. The taper applies to the amount above the nil-rate band, not the nil-rate band itself.

Gifts to spouses remain unlimited and exempt from IHT regardless of value. This makes lifetime transfers to a surviving partner a useful planning tool without triggering any tax consequences.

Will Planning Considerations

Ensuring wills direct the family home to direct descendants preserves eligibility for the residence nil-rate band. If the home passes to someone outside this definition, such as a sibling or friend, the RNRB is lost entirely.

Discretionary trusts, once common for nil-rate band planning, have become less necessary since the transferable bands were introduced. Simpler will structures often achieve better outcomes for married couples.

Life insurance written in trust can provide liquidity to pay any IHT liability without adding to the taxable estate. This is particularly relevant when significant assets are tied up in property or difficult-to-sell investments.

IHT Timeline: First to Second Death

Understanding the sequence of events helps couples plan effectively for inheritance tax on the second death.

1. First death of spouse or civil partner: The estate passes to the surviving partner entirely free of IHT under the spouse exemption. No nil-rate band is used at this stage.
2. Probate administration of first estate: Executors handle the estate, typically with no IHT liability if everything passes to the surviving spouse. Records should be maintained for future claims.
3. Surviving partner’s lifetime: The surviving spouse may make gifts, update their will, or undertake planning. The estate grows, and records of the first death remain important.
4. Second death: Executors calculate the estate value, determine transferable bands from the first death, and submit IHT400 with any claim for transferred allowances via IHT402.
5. Payment deadline: Any inheritance tax due must be paid within six months of the end of the month in which the second spouse died. Interest accrues on late payments.

Confirmed Rules vs Potential Changes

The current rules are confirmed through official government publications and apply to England and Wales. Anyone with specific circumstances should verify current rules directly with HMRC or a professional adviser.

Full Analysis: How IHT Works for Surviving Spouses

When the first spouse dies, the survivor typically inherits the entire estate. Because this transfer qualifies for spouse exemption, no inheritance tax is due and the deceased’s nil-rate band remains unused.

The survivor’s own estate now includes everything they owned jointly, plus any new assets acquired. When they die, the calculation combines their own nil-rate band with any unused portion from their late partner.

This mechanism recognises that couples often leave everything to each other first, then to their children. Without transferable bands, the first death would waste the nil-rate band entirely, resulting in more estates paying IHT on the second death.

Expert Sources and Quotes

HMRC guidance confirms that transferable bands apply when the first death qualifies for spouse exemption, with claims made on the second death. The government’s nil-rate band documentation provides the authoritative figures for current thresholds.

Professional sources including Ross Martin and Simply Law provide detailed worked examples showing how transferred bands can eliminate IHT liability for estates within the combined thresholds.

Financial advisers such as M&G Investments note that the rules particularly benefit couples where one partner had a modest estate, as the surviving spouse can claim their full nil-rate band.

What’s Next: Planning Steps

Couples should review their wills to ensure the family home passes to direct descendants if they wish to preserve the residence nil-rate band. Keeping records of the first death, including any IHT forms filed, simplifies claims later.

For those with estates approaching or exceeding £2 million, seeking professional advice helps navigate the taper rules and explore options such as lifetime gifting or life insurance in trust.

HMRC’s online tools and the GOV.UK inheritance tax guidance provide starting points for understanding personal circumstances. Professional solicitors and tax advisers can offer tailored recommendations.

The rules for England and Wales are well-established, but individual circumstances vary considerably. What applies in general terms may require adjustment for specific situations involving trusts, business assets, or unusual estate compositions.

Summary

Inheritance tax on the second death of a parent follows different rules than the first death. The surviving spouse can claim unused nil-rate band and residence nil-rate band allowances from their late partner, potentially doubling tax-free thresholds to £650,000 nil-rate band plus £350,000 residence nil-rate band for qualifying couples.

Current thresholds are fixed through 2029/30, providing certainty for planning purposes. The spouse exemption on the first death preserves these allowances for transfer, making the second death the point where IHT liability typically emerges.

For Rates and Allowances comparisons and general financial context, these IHT rules represent one component of broader financial planning for couples.

Frequently Asked Questions