Anything to do when returning security deposit?

[Sam Faas]

I had a situation recently where the tenant and I, mutually agreed that a move out was in their best interest.  One of the conditions I agreed to was returning their full security deposit without condition after 10 days, once they move out.

I haven't done this before, so I  will be giving them a check with a line in the memo saying the security deposit return and making them sign an acknowledgement that the security deposit has been returned in full.

Anything else I need to do when I return the security deposit?