joint wills

[janeybabes]

Is a joint will (i.e a one document will) between a married couple legal or does it become invalid when the first person dies?

[dzug]

A one document will is not possible in the UK so it's not legal in the first place. 'Mirror' wills are what is normally done. The first death does not automatically make the mirror will invalid - but it will almost certainly need revising, particularly if its only beneficiary is dead. (It will still be valid as to the appointment of executors, for example)