Once the divorce becomes final and irrevocable between the husband and wife, can both the parties marry again? If yes, under what circumstances and with what conditions? Is the halalah not necessary in this case?

Answered according to Hanafi Fiqh by Darulifta-Deoband.org

بسم الله الرحمن الرحيم

(Fatwa: 1258/980/D=11/1434)

The relation of nikah comes to an end when three talaqs (mughallazah) occur. Now their nikah cannot be valid without a Shariah halalah. The woman should marry after completing her iddah with any other man who should do intercourse after the nikah, and then if the second husband gives her talaq or dies then the woman may marry the first husband after observing her iddah. This is called halalah.

Allah knows Best!

Darul Ifta,
Darul Uloom Deoband