The phrase "legally invalid" is correct and usable in written English.
You can use it to describe a document or a contract that is not legally binding or enforceable because it is not legally valid. For example, "The agreement was declared legally invalid due to a lack of signatures."
It is legally invalid because it contravenes the legal base of regulation that expressly excludes legislation "affecting the rights and interests of employed persons".
Peers also discussed Labour peer Lord Harrison's call for humanist weddings, which are legally invalid in England and Wales but legal in Scotland, to be recognised in law for same-sex and heterosexual couples,.
Self-treatment, even if done properly, is legally invalid.
He appears to have declared Appleton's appointment by Shaw to be legally invalid.
This made any bonds that formed between the boys legally invalid, the judges said.
The film starred Carole Lombard and Robert Montgomery as the eponymous bickerers who discover that their marriage is legally invalid.
Finally, with the leavers backing away from some of their campaign promises and statements, can the EU referendum result legally be declared invalid?
HRC's Warbelow added: "Davis's legal team simply saying the licenses are invalid is not legally sufficient to make them invalid".
Lord Justice Davis and Mr Justice Wilkie found decisions made by the police forces were so legally flawed that they were "invalid and of no effect".
Some of these philosophers think that constitutional law expresses the ultimate criteria of legal validity: because unjust remedies are constitutionally invalid and void ab initio, legally speaking they never existed (Waluchow).
(It notes, as part of a technical argument, that marriages between first cousins are legally valid in some states and invalid in others).
