Sign an annual or six month or whatever  service contract with the person that has all of this detailed and have them invoice you for each rental.

I'm unsure about your area,  but in mine,  if the repairs were made by a licensed contractor and you could obtain copy of invoice,  you can contact the contractor to fix their faulty repairs or report them. 

I am wondering what's the best way to document my payments to them since it's likely that they can't provide any official invoice and I will be paying in cash or check.

Rent is invoiced through the website.Additionally, its run by a tech company and part-time landlords based in the Oregon area, and I expect them to cater primarily to landlords.It creates and application link, tenant puts their history etc.

Plus I don't have to hear the dang thing running all the time either.I don't know about your area, but if the cost isn't that much of a difference to go tankless and the lifespan is relatively the same, I'd go tankless.

I just got this email from the seller's agent tonight.My client emailed the following and included the attached:I went back into the records and either didn’t recall the pump out correctly or lost the invoice record.

Garbage/sewer, water are invoiced all together to you by the City of Houston and most of the time you have to pay for it due to one meter per building.

They will either tell us on the phone what is being purchased or will fax us the invoice for us to approve before allowing the contractor to make the purchase.  

This means:You must use a property manager; you cannot manage the property yourself.You may not personally do work on the property; a third party has to do it and the invoices paid by the custodian or the property manager.You may not mix personal and IRA funds or the entire transaction may become an "early withdrawal" from your IRA and taxed as such.You must report the market value to the custodian each year.Rental income flows into your IRA, which you can utilize according to applicable IRA rules.

Dang, that isn't a simple deal, that is a spectacular deal!