The current situation (since the 2015 Budget) is set out below.
This tax is payable on estates above a specified limit, but if the estate is inherited by a wife or husband no tax is due. It is also payable on any non-exempt gifts made in the seven years before a person's death. If you give away a specific sum of money (no matter how large) and live for more .than seven years afterwards, then no tax is payable.
However, if you die during the seven-year period some tax is payable on a reducing scale, depending on how long you live during that period.
There is an annual total exemption of £23,000 relating to gifts you may make. On marriage/dowry gifts this is to the total value of £25,000 from a parent, £22,500 from a grandparent and £21,000 from others. There is a small gifts exemption for gifts of up to £12250 a person per year.