How is Zakat to be paid on commingled funds from the incomes of both spouses and the shop's income, all of which are invested in the shop's merchandise, given that there is no liquid money that has completed a full year?

The owner of the business must record the time when his money reaches the nisab. Then, he must pay zakat on all the money designated for trade, in addition to any other zakat-eligible money, upon the completion of the hawl (one lunar year), unless the money falls below the nisab during the hawl. Goods are to be assessed at their market value, and one-quarter of one-tenth (2.5%) is to be given out.

If the goods were purchased from the growth of the business, their zakat is due with the hawl of the business, and the profit of the business follows its origin in terms of zakat. However, if the goods were purchased with money acquired from sources other than business profit, then a separate hawl must be calculated for these goods, or all of it can be paid as zakat at the hawl of the original capital.

If the wife donates her income to her husband as assistance, the zakat is incumbent upon the husband. However, if the wife has an independent share in the business, then each partner pays zakat on their own share.