I agree with Adrian. In addition, although there is no inheritance tax payable now, a deed of variation with a payment on the side to "fulfil his side of the bargain" leads to a potential inheritance tax problem later. In these circumstances, since the will has been varied, the payment from brother to sister would count as a gift - not as an inheritance from the parent. As such, if the brother were to die within seven years, that gift would count as part of his estate. If that meant that the brother's estate were to be large enough to qualify for inheritance tax, then inheritance tax would be payable on that gift. I suggest that is not a desired outcome!
Andrzej Kowalski ● 2024d