Powers of Attorney Act 1980

The donee of a power which has been revoked who acts in pursuance of the power shall not incur any liability by reason of the revocation either to the donor of the power or to any other person:

unless the donee of the power has actual notice of the revocation of the power; or

if the power has been created by an instrument which has been registered:

and the act is an act with respect to a dealing in relation to land (a lease for a period of not more than one year excepted) –

unless an instrument revoking the power has been registered; or

in any other case – unless a period of 30 days from the registration of an instrument revoking the power has elapsed.