A will may be challenged if it is not in the proper legal form or is not properly executed.
It can also be called into question if the person who wrote it was not of sound mind, lacked knowledge and approval of the contents of the will or was put under undue influence or fraud.
The Inheritance (Provision for Family and Dependants) Act 1975 enables people who fall within the categories set out in the Act to bring a claim for financial provision from the estate. There may be justifiable reasons for omitting someone from a will and it is not necessarily the case that a claim would be successful just because a person falls within the act.
In every case it is important to take early advice as there are time limits for some claims and all claims can be prejudiced by delay.