Zakat is not paid for this money when taking possession of them. Rather they are added to his other money that is subject to Zakah and then Zakat is given out for all the money when the Hawl has passed, beginning from when the Nisab was completed. Whatever benefit he receives this money during the Hawl, Zakah will be paid for that too at the end of the Hawl, even though the Hawl is not complete for each and every part of this money, so long as a Hawl has passed over the ownership of the money as a whole for the one who pays Zakah. The value that should be paid is a quarter of a tenth, 2.5%.

https://www.youtube.com/watch?v=Ah3PxnnUCLY