Question
My mahr is not fully paid — part is overdue, part set as payable on demand/deferred. As the wife, do I owe zakat on this receivable?
Ruling (Fatwa)
Short answer: Mahr is a debt owed by the husband to the wife — reckoned by the debt rules: (a) a solvent husband who would pay on request makes it a 'strong debt': if you hold nisab, add it yearly to your reckoning (or settle the accumulated years upon collection); (b) customarily deferred mahr (not claimable before divorce/death) or an insolvent husband makes it a 'weak debt': no zakat before receipt, then a fresh hawl.
Details: Mahr is the wife's exclusive property — the Quran declares it fully hers; neither husband nor family may touch it without her free consent. The common practice of recording mahr as 'received' while never paying leaves it a real outstanding debt on the husband, to be paid or genuinely forgiven before death. Her voluntarily remitting part of it is valid (the end of 4:4); remission extracted by pressure or embarrassment is not.
Evidence: Quran 4:4; Sahih al-Bukhari 2387 (whoever takes people's wealth intending repayment, Allah repays for him); the strong/weak debt distinction from the athar of Uthman (Muwatta) and the debt fatwas of the Permanent Committee and Shaykh Ibn Baz.
For complex individual cases, consult a qualified scholar.
References
Quran
Quran 4:4
Hadith
Sahih al-Bukhari 2387
Fiqh
Permanent Committee; Ibn Baz on debt zakat