You can't have one without the other. From Colorforth:
"The reason I wanted a written contract was not that I don't trust Leckrone, but to get a mortgage to complete my house. Understandably, banks require you to prove your income. I had been receiving from TPL a $15K/mth advance on royalties for living expenses. In 2007 I purchased land in Incline Village. Rather than pay $2M he owed me, Leckrone agreed to pay a mortgage for me. Thereafter I received $30K/mth, $15K advance and $15K mortgage."