Yes. There are five grounds upon which you can challenge the validity of a Will:-
a) The deceased did not have the necessary mental capacity at thetime the Will was made;
b) The deceased did not know or approve the contents of the Will;
c) The deceased was coerced or unduly influenced into making the Will;
d) The Will is a forgery or it was fraudulently created;
e) Lack of proper formalities – you can contest the validity of a Will if it was not correctly witnessed or otherwise was not properly executed.
Please note there are other claims you can bring against an Estate in addition to disputing the validity of a Will. These include seeking to enforce a promise made to you by the deceased, a claim for reasonable financial provision where the deceased has not made reasonable provision for you and/or asserting an interest in property or assets owned by the deceased to which you have contributed.