Seller Financing and Mortgages "Subject to"

[Louis L.]

I'd love to hear others' experiences creating a (secondary) mortgage with the seller of a property to finance a portion of the down payment. I am pondering the situation where the seller finances 10%, I put in 10% and the bank covers the rest.

Legally, how do you go about this process-who should I contact first? I hear some people make informal agreements but Id like it to be as official as possible. I understand the mortgage would be "subject to" and the seller would need to be comfortable with that.

Additionally, would it be possible for the seller to theoretically sell this mortgage on the secondary market? Does anyone have experience or know about this? Is it feasible/possible/common?

Thanks in advance!