The liability to pay IHT may be imposed (by the action of the Inheritance Tax Act 1984 s199 and s200) on any of the following:
If a transferor makes a chargeable transfer during his lifetime, he is principally liable to pay the tax (see 1.15).
If the transferor does not pay it, the transferee becomes liable to pay the tax.
If the tax remains uncollected at the date of death of the transferor, the transferee remains liable.
If a PET becomes chargeable because the transferor dies within seven years of making it, the transferee is liable to pay the tax. 
In practice, the personal ...