Pay them as you would a contractor, with quote/invoice and check matching said quote invoice.

I definitely notice that the job price goes up by the size of the building.For example, I just noticed that on one invoice, they didn't put the model number but it was a unique part. 

Find a management company (LeParulo was decent, and I haven't heard otherwise lately...) that invoices you, and doesn't have in house maintenance.

Now you not only have me procrastinating doing invoices/bids but contemplating visiting/moving to California. 

Fast forward 3 months, I get an invoice from them for well over $1,600 for those repairs.

What really made it viable were two things: offering "easy financing" and then having your mortgage broker set up the financing for the buyer (doesn't exist now), and second, using a "special invoice" so that you could get paid on the HUD statement.

 - Where all invoices (electronic and paper) can be stored (and the date tracked) - Heck maybe some automation :-)- Calls from tenants recorded (call, time and date and what was reason, and resolution)- Rent tracking, amount, date, late fee, maybe an auto notification sent to tenants that have not paid and a custom message, like "It is the fifth day of the month, and per the terms of your lease, a late fee of $XX will be assessed to your rental payment."

I read the fees page, but they have different fees for invoices by e-mail, online payments, and mobile app payments.

But, if I include it in my HM loan, it adds another 12k onto my losses, and I have to deal with the invoice clearance and inspection procedure to get my rehab funds.If I partner with someone who puts in the rehab funds up front, I can actually save myself some money by utilizing a crew that I normally couldn't afford using the HML system, increasing my chance of making this flip work the way I want, and allowing me to utilize my own funds as a safety net and/or start another flip.Kind of a great deal, huh?

False invoices, materials delivered on site that are then "stolen", etc.