Some scholars are of the opinion that people are not required to pay zakah on the income they earn in return for their work, unless they have saved from it an amount of money equal to (or exceeding) the nisab (minimum amount on which zakah is due) and a whole lunar year has passed while they have this amount. Some other scholars believe that zakah is to be paid on this income as soon as it is got without waiting until the lunar year passes. Other scholars are of the opinion that the earners may add the money they save from their income to the zakatable wealth they already have and pay zakah on the whole amount at the end of the lunar year set for the original wealth. The zakatable amount to be paid here is 2.5 percent.
Sheikh Faysal Mawlawi, deputy chairman of the European Council for Fatwa and Research, states: The majority of scholars, including the Maliki, Shafi`i, and Hanafi scholars, believe that no matter how high the incomes people earn from work are, the incomes are not subject to zakah unless the earners save from these incomes an amount that reaches nisab and a lunar year passes while having this amount, or according to the Hanafi scholars, the amount reaches nisab in both the beginning and the end of a lunar year.

However, there are some eminent Companions, righteous predecessors, and knowledgeable scholars—such as Ibn `Abbas, Ibn Mas`ud, Mu`awiyah, `Umar ibn `Abdul-`Aziz, Az-Zuhri, Al-Hasan, Makhul, Al-Awza`i—who are of the opinion that if a person earns enough so that after expenses are deducted the nisab is reached, he is to pay zakah on that remaining amount as soon as he gets his income. Analogous to this, Imam Ahmad ibn Hanbal was reported to have said that a lessor is to pay zakah on the rent he gets from the lessee as soon as he gets it. This view is held also by An-Nasir, As-Sadiq, and Al-Baqir, eminent imams of the Prophet’s descendents, as well as by the eminent scholar Dawud Az-Zaheri.
It is worth mentioning that Caliph Mu`awiyah and Caliph `Umar ibn `Abdul-`Aziz would collect zakah from people on the salaries and grants that they received from the treasury of the state. This means that both caliphs acted upon their individual point of view in this regard without the companions and righteous predecessors opposing them.
Taking into account that people get their salaries and incomes in money, the nisab on which zakah to be paid here is estimated as the value of 85 grams of gold. If one gets an income that reaches this amount after excluding one’s expenses, one is to pay zakah on it each time it is received. The amount of zakah to be paid here is 2.5 percent.
If the income does not reach the nisab, one is to save the unspent income along with other amounts saved from one’s income and to pay zakah on the whole amount at the end of the lunar year if it reached the nisab and remained for one year. If one uses up the income one gets, one is not required to pay zakah on it.