What I am looking to show is proof of transaction, provide receipts  for customer, ability to use a card, easy to use.

Part of contingencies are proof of income, (bank statements copies of rent checks), full inspections, estoppels, credit checks on tenants, confirmation of Sec 8 inspection approvals. 

If aunt sally gave you $20 for Christmas and you deposited it in the bank they are not asking you for proof or an explanation.

He accepted my tax return as a proof of income.

That way if something shady ever does happen you have proof that you had an agreement.- Mike

My ex-tenant in TX was evicted, owes me $3.8K, but is a deadbeat (alcohol issues) and cannot keep up a job. 

We have great credit, no bankruptcies, and no debt, but are switching careers (from church ministry to full time REI) after 25 years, so we obviously don't have the typical "proof of where monthly loan payments are coming from".

Your story is proof of that.

If you've owned anything in the past I would leverage that, brokers are going to look for proof of funds, or a schedule/list of your owned assets.

The lender only needed proof of insurance to close, in my case they allowed a $10,000 deductible on the flood policy which helps keep the premiums down.