There is no time limit within which you need to bring a claim to challenge the validity of a will. So you can challenge a will before or after probate has been obtained and a will can be overturned after probate.

What grounds can a will be contested?

The main grounds to contest a will are: Lack of testamentary capacity (the mental capacity needed to make a valid will) Lack of due execution (a failure to meet the necessary formalities i.e. for the will to be in writing, signed and witnessed correctly)

How long before a will Cannot be contested?

There is a strict time limit for contesting a Will. You must bring a claim within six months from the date of the grant of probate. Sometimes the court allows claims after this this period, but it is important to seek legal advice as soon as possible in order to find out where you stand.