Fiqh-us-Sunnah Volume 3, Zakaat and Fasting, Fiqh 3.017A.

Abu Hanifah and Malik maintain that the rent is not payable to the landlord at the time of the contract but at the expiry of the renting period. Thus, the landlord who rents out a house should pay the zakah on his house rent, provided the fixed amount meets the following conditions: receiving of the money and completion of nisab at the end of the year. The Hanbaliyyah think that once the contract is concluded, the landlord is entitled to have rent. Thus, if someone leases his house, the zakah is due upon its fixed rate reaching a nisab at the end of the year. This is so because the landlord has the right to spend the rent the way he wants to. The possibility of cancelling the lease does not invalidate the obligation to pay zakah. This case is similar to the case of dowry before the consumption of a marriage. If the rent is an arrear rent, then it should be treated as a debt either as paid or postponed. In al-Majmu’, an-Nawawi says: “If somebody leased a house and was paid in advance, he should pay its zakah on receiving it. This is uncontroversial.”