Delayed security deposit should I accept tenants or find new ones

[Michele G.]

4 tenants (students) were supposed to pay security deposit today for April 1 move in. I have not signed lease yet as I want all signatures, co-signers and security deposit in place. 

They just let me know they can pay half on April 1 and the other half next week after they move in. 

What would you do in this situation and what would you tell the prospective tenants? 
 
thank you 

[Kim Meredith Hampton]

I have made it a hard fast rule to never let anyone move in until the sec dep, pet dep, rent and utilities are turned on in their name. I’ve been burned too many times. This always screams red alert when they already can’t pay something