Source:
Fatāwā Muḥammadiyyah, Vol. 1, Page 567
Question:
If a mother and her son live together in the same house, share the same kitchen, and jointly run a business — yet both possess separate gold jewelry — should Zakat be calculated on their jewelry collectively or separately?
Answer:
Al-ḥamdu lillāh, waṣ-ṣalātu was-salāmu ʿalā Rasūlillāh, ammā baʿd!
◈ If the mother and son live together, share the same household expenses, and their business and financial affairs are joint, then their gold jewelry will be considered combined (joint ownership) for the purpose of Zakat.
Hence, Zakat should be calculated collectively on the total amount of jewelry.
◈ However, if the mother and son’s earnings, business, or income sources are separate, then each person’s jewelry will be considered independent property.
In this case, each individual must pay Zakat separately, only if his or her personal jewelry reaches the Nisab (minimum threshold).
Additional Note
For Zakat to be obligatory, the son does not necessarily have to be an adult (bāligh).
If the Nisab amount is complete, Zakat becomes obligatory even on the wealth of a minor or orphan, whether male or female.
هٰذَا مَا عِندِي وَاللّٰهُ أَعْلَمُ بِالصَّوَابِ
This is what I hold to be correct, and Allah knows best what is right.
