Age 18 to 25 Special Trust or a Bereaved Young Person's Trust (or section 71D settlement) is a trust created within a will with an age condition set between 18 and the beneficiary's 25th birthday. To qualify as an Age 18 to 25 Special Trust, the trust must satisfy certain conditions as per section 71D IHTA 1984. These conditions include the beneficiary becoming entitled to the trust property no later than their 25th birthday, receiving all income arising or any income applied while under 25, and being entitled to all income arising while living and under 25.

Age 18 to 25 Special Trusts are ideal for parents who are comfortable with their children inheriting absolutely no later than 25 and offer greater flexibility than Bereaved Minor Trusts. These trusts are slightly less IHT effective than Bereaved Minor Trusts but offer benefits over relevant property trusts and Immediate Post Death Interests. If the trust's assets exceed the nil rate band of £325,000 and continue beyond the beneficiary reaching 18, there will be an exit charge when assets leave the trust, either through capital distributions or the trust's termination.

The exit charge for beneficiaries between 18 and 25 is calculated similarly to that of a relevant property trust, with a maximum rate of 4.2% compared to 6% for an ordinary relevant property trust. Age 18 to 25 Special Trusts are qualifying settlements for the Residence Nil Rate Band (RNRB), so it is safe for a testator to leave their qualifying residential interest  on either of these trusts.