Gender Recognition Act 2015
Disposal or devolution of property
20. (1) The fact that a gender recognition certificate is issued to a person shall not affect the disposal or devolution of property under a will (including a codicil) or other instrument executed before the date this section comes into operation.
(2) Notwithstanding any rule of law, a disposition made by will or codicil executed before the date this section comes into operation, shall not for the purposes of this section or section 22 be treated as made after that date by reason only that the will or codicil is confirmed by a codicil executed after that date.