I suppose i) most people won't have enough in the way of assests for this to matter, and ii) those who do know about this, but there was an interesting little piece on how to avoid inheritance tax if your death is linked to military service, even if 40 years have elapsed. The revenue (apparently) are pretty liberal in interpreting the rules, you (or more accurately, your heirs) have to show a plausible link. It's near the end of this weeks prog on Moneybox on Radio 4. Should be repeated tonight (Sunday 15/11) at 2100, although the actual piece is near the end of the prog. Apparently a spouse can inherit the exemption.