Why the second death is the moment that matters — and what families need to know.
When the first parent dies, there is usually no inheritance tax to pay. Everything passes to the surviving spouse or civil partner tax-free under the spouse exemption. There is no limit on how much can transfer — the entire estate is exempt.
This means most families do not think about inheritance tax at the first death. The paperwork is completed, the estate transfers, and life continues.
It is the second death that changes everything.
When the surviving parent dies, there is no longer a spouse to inherit tax-free. The full combined estate — the home, savings, investments, pensions, and everything else — is assessed for inheritance tax in one go.
For many families, this is the first time they discover there is a significant tax bill. The estate may have grown in value over the years between the two deaths, property prices may have risen, and pension rules may have changed. The surviving parent may never have revisited the plan that was put in place years ago.
Planning point. The spouse exemption is a deferral, not a solution. It postpones the tax until the second death, when the full combined estate is assessed. For most couples, the second death is where the real planning needs to happen.
Every person has a tax-free allowance called the nil-rate band. For 2025/26, this is £325,000. It has been frozen at this level since April 2009 and will remain frozen until at least April 2031. Anything above this amount is taxed at 40%.
There is also an additional allowance called the residence nil-rate band, worth £175,000 per person. This applies when the family home passes to direct descendants — children, stepchildren, adopted children, foster children, or grandchildren.
Together, these give a single person up to £500,000 of tax-free allowances.
When the first parent dies and everything passes to the surviving spouse, none of their tax-free allowances are used — because the spouse exemption means no tax is due. Those unused allowances do not disappear. They can be transferred to the surviving spouse and claimed when the second parent dies.
The transfer is based on the percentage that was unused, not a fixed amount. If the first parent used none of their allowances, the surviving spouse inherits 100% — effectively doubling their own allowances.
However, this only works if the home passes to direct descendants and both wills are structured correctly. The transfer is not automatic — the people dealing with the estate (the executors named in the will) must claim it.
There is a catch that many families do not expect. If the total estate exceeds £2 million, the residence nil-rate band is tapered away. For every £2 the estate is above £2 million, £1 of the residence nil-rate band is lost.
For a couple using both sets of allowances, the full residence nil-rate band disappears entirely once the estate reaches £2.7 million.
The taper trap. In this range between £2 million and £2.7 million, the effective tax rate is 60% — significantly higher than the standard 40%. Many families assume they will receive the full £1 million allowance, only to discover the taper has reduced or eliminated part of it.
The period between the first and second death is the most important window for inheritance tax planning. Once the surviving parent has inherited the full combined estate, there are several steps worth considering:
Review the will. The way the estate is structured in the will directly affects which allowances are available. A solicitor experienced in estate planning can ensure the will preserves access to both nil-rate bands and both residence nil-rate bands.
Consider lifetime gifting. The surviving parent may be in a position to make gifts during their lifetime. Annual gift exemptions, gifts from surplus income, and larger gifts that survive seven years can all reduce the estate over time.
Check pension arrangements. From April 2027, unused pension funds may be included within the estate for inheritance tax purposes. This is a significant change that could increase the tax bill for many families.
Understand the property position. How the family home is owned, whether it passes to direct descendants, and whether it qualifies for the residence nil-rate band are all critical questions.
Get professional advice. The interaction between allowances, gifts, pensions, property, and trusts can be complex. A qualified inheritance tax specialist can review the full picture and identify planning opportunities specific to your family's circumstances.
If you have recently lost a parent, or if you are the surviving spouse thinking about what comes next, the first step is understanding where you stand.
Our free inheritance tax calculator estimates your liability in under five minutes. It takes into account your allowances, the transferable nil-rate band from a deceased spouse, and the residence nil-rate band — and shows you which planning strategies may apply to your situation.