Where the property falls within IHTA 1984, s. 31(1)(a) (books, works of art etc.), the requisite undertaking is threefold, and subsists until the person beneficially entitled to the property dies, or the property is disposed of by sale or gift or otherwise (s. 31(2)).
The property will be kept permanently in the UK, and not removed temporarily except for a purpose and a period approved by the Board. Applications to remove property for a temporary public exhibition abroad should be made to HMRC IHT. The Heritage memorandum notes that in the case of objects more than 50 years old, an export licence may be required.