Lender needs proof of deposit and first months rent??

[Ian K.]

So I'm renting out my primary home as we have just gone under contract on a new place.  I have two years of landlording experience so I can use the income from my current primary rental.  My lender said that he needs both evidence of the deposit and the first months rent.  Being that I have to have evidence of this before I can close, I can't actually move the tenants until after they have submitted both.  

Questions: 

Is the best way to have the renter provide a deposit check dated on the day of signing the lease agreement and post dated a second check for the day of move in for the first months rent?

Or is is okay to ask for both up front dated on the signing of the lease?

I'm in Colorado in case that matters. 

Thanks for your help!