According to a judgment PLD 1980 KHI 477 , a wife is entitled to claim deferred dower amount only in two conditions.
1. In case of death of husband
2. In case of divorce
A wife in a relationship cannot demand deferred dower from her husband. The same principle is present in Muhammadan Law book written by Mullah in sections 221 to 225. However, on the contrary dower amount is the right of woman which she can claim from her husband as an amount against the consumation of marriage. There are many judgments that declare a marriage incomplete unless the dower amount is paid. For more on this feel free to ask any question at email@example.com
Salman Yousaf Khan