بسم الله الرحمن الرحيم
(Fatwa: 1554/1558/M=1430)
Yes, the salary, which was not received after being due and one hopes to receive the same, will be liable for Zakah. But one will be asked to pay it after receiving the same, however if one paid its Zakah in advance it will be valid.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband
