15th of Month Lease Start, Security Deposit & First Month $?

[Susan Michael]

Hi all. I have prospective tenants who are willing to commit by 5/20/18 for a rental that's available 6/1/18. They do not want the lease to begin until 6/15/18 and are willing to do a 12.5-month lease, taking it to 6/30/19. They have paid through 6/30/18 on their current rental with another landlord. Would you:

a) collect full security deposit and first month on 5/20/18,

b) collect full security deposit on 5/20/18 and first month no later than 6/15/18,

c) collect full security deposit plus half first month's rent on 5/20/18 and 2nd half of first month's rent by 6/15/18?

I am treating the security deposit as a non-refundable hold either way - it would convert to an actual security deposit once the lease starts.

Thanks, Susan