Hello I have a seller who is ready to contract with me to sell his house however the agreed closing date is many months from now.

When I sell to buyers, they make their checks out to me personally.I formed an LLC today (today is the Effective Formation Date) and I notified all my buyers to begin making their checks to me payable to my LLC (instead of me personally).However, what is the proper thing to do with those checks my buyers *already* wrote a couple weeks ago (that are currently in the mail on their way to me) that have been endorsed to me personally? 

I can see when the last recorded sale date was and even permit information, which definitely helps.

Or is it legal to use current leases content just changing my name and dates, print it out and have them signed?

In the state of Florida is it legal to ask applicants for date of birth and social security number?

It's a little dated but still really good book on creating systems.

I am brand new to real estate investing and hope to learn a lot from this community and fellow people in the greater Seattle area.

They sent me a copy of the release of mortgage which was dated March 2015!

Fellow Washingtonian here.

You would also have the ability to 1031 out of them at a later date and defer any taxes.