Will contest describes proceedings to challenge the validity or effect of a will. The term is descriptive, not statutory. In England & Wales and Northern Ireland this is “contentious probate”; in Scotland it proceeds by an action of reduction of a testamentary writing; in Ireland it is a probate action under the Succession Act 1965.Typical grounds include: lack of testamentary capacity (Banks v Goodfellow applied in E&W/NI; equivalent Scots principles), undue influence, want of knowledge and approval, failure of due execution (Wills Act 1837; Requirements of Writing (Scotland) Act 1995; s.78 Succession Act 1965 (Ireland)), forgery, or revocation.Procedurally, a caveat is often entered to prevent a grant of probate/confirmation (E&W/NI/Ireland), followed by a probate claim (E&W: CPR Part 57) or, in Scotland, an action in the Court of Session or sheriff court for reduction, with proof on the validity issues. The propounder must prove due execution and knowledge and approval once capacity is put in issue; the burden may shift on suspicious circumstances.A will contest is distinct from family provision claims (E&W: Inheritance (Provision for Family and Dependants) Act 1975; Ireland: s.117 Succession Act 1965), which do not impeach validity but seek redistribution. Limitation for validity challenges is generally flexible, though delay, laches and grants acted upon may affect relief.