Contractor invoices can be scanned and uploaded in PDF, and a spreadsheet can be used to accumulate costs.

I think I can handle the equitable interest concern with a simple clause in the document stating that the payments do not vest any interest in the property, but to avoid creating taxable income while still having a legally binding agreement, I'm struggling.The best I've come up with so far is an agreement that is titled simply "Agreement" and it outlines that she is reimbursing me for half of all expenses and I would invoice her for half of all the bills that came in each month related to the house.Would a "reimbursement agreement" pass the sniff test with the IRS if it ever came up?

Make sure to pay off those invoices as soon as they come in.

So he sent invoices to them for the $3 they still owe us. 

He sent us an invoice to get drawings and permits pulled and we paid him for it. 

I know there are cash-out refi programs where once I've made the $50K in payments, and I can show payments/invoices to a contractor for said repairs (I'd have to fake this which I don't want to do), I can go get the home re-appraised with the capex done and apparently this process is relatively simple, costs around $3,200 per house and most of the time the homes appraise how you want it.

Upon pushing them for invoices they decreased it to $87k but said more is coming once the framing is complete.  

**NEVER PAY A SUB 50% upfront**1st Always have a proposal from the esteemed subcontractor it vendor, with their information - qualify the sub no matter how big or small the job is:• look up their State License on your state license board - make sure it’s active, not suspended • Let them send in their insurance information with your property as the additionally insured • keep track of any Preliminary notices that they may send to you 2nd Come to a written agreement/contract of a payment schedule* - with less 5% retention on each invoice until close of project scope A timing schedule is also really good to have in your contract that way they are not just prolonging the job.

Invoice factoring is a method of monetizing accounts receivable to give business owners immediate access to the revenue they are owed.

Get comfortable with uncertainty, or be explicit about your expectations when working with a contractor (weekly visits/photos, invoices prior to payment, etc) - don't make assumptions.