LAW 101: Disallowed Wills

Wills shall be disallowed in any of the following instances:

1. non-compliance of legal formalities;

2. the testator was mentally incapable of making a will, at the time of its execution;

3. if it was executed through force or under duress, or the influence of fear, or threats;

4. if it was procured by undue and improper pressure and influence on the testator;

5. if testator’ signature was obtained by fraud; or

6. if the testator acted by mistake or did not intend that the instrument he signed should be his will at the time of its execution.

Source:
Art. 839, New Civil Code.