Q: If a man marries a woman who has not sat for her Iddah, will the Nikah be valid?
A: Observing Iddah is a Quranic obligation upon a woman. Nikah to a woman whilst she is observing her Iddah is invalid.
If a woman failed to observe her Iddah, she will be sinful. However, making Nikah with a woman whose Iddah period has expired completely is permissible.
And Allah Knows Best
Darul Ihsan Fatwa Dept.