Proving a will refers to the legal process of establishing that a document is the valid last will and testament of a deceased person, so that it can be used to administer the estate. In practice, this is achieved by obtaining a grant of probate (England and Wales, Northern Ireland, Ireland) or confirmation (Scotland) from the court.The concept is grounded in probate and succession legislation and procedure, rather than being a single defined statutory term. It typically involves showing that the will complies with formal execution requirements, that the testator had testamentary capacity and knowledge and approval, and that there is no undue influence, fraud or later revocation.In England and Wales, Northern Ireland and Ireland, proof is usually by the oath or statement of the executor, supported where necessary by affidavit evidence (for example, where witnesses cannot be traced or execution is irregular). In Scotland, the court must be satisfied that the will is formally valid and that the executor-nominate is entitled to confirmation.Proving a will is essential to establish the executor’s authority, collect and distribute assets, and avoid an intestate or partial intestate estate.