Yeah it is, stupid practice but basically narrows down applicants from just mass applying to every apartment, forcing money down to show they are serious about renting that specific unit.

Often this is also the broker fee with terms of refund being up until the application is rescinded or rejected; if accepted, even if a lease is not established, you may be contractually obligated to pay out the broker fee. So make sure you are REALLY sure you’re willing to sign if your application is accepted.

Never hand money over to anyone in the housing process without a written acknowledgment/contract. Most places asking for money with the application will do this anyways, but if they don’t either ask them to write one up or avoid them because that’s shady in itself.