Zakat on receivables
In one sentenceZakat on money others owe you. A debt expected to be collected is added to your wealth and zakated every Hawl, and a doubtful debt is not zakated until it is received, according to many scholars.
Simply put
A debt owed by someone able to pay and not delaying is as if it were in your hand, so you add it to your zakatable wealth.
A debt owed by someone insolvent, who denies it or who keeps delaying, is not zakated until you receive it. Then you pay Zakat on it when received, according to many scholars.
Worked example
On the Hawl day, a trader is owed 100,000 SAR by his customers: 70,000 SAR by regular customers and 30,000 SAR by one defaulting customer.
Collectible debts70,000 SAR
Doubtful debts (not zakated now)30,000 SAR
Zakat70,000 × 2.5%
Zakat on receivables this Hawl1,750 SAR
Don't confuse it with
Accounts receivableAccounts receivable is an accounting balance, while Zakat on receivables is a religious ruling that separates collectible debts from doubtful ones.