Just because something is written in a way that sounds official, doesn't make it legal.And....to make a long story longer....just because the plumber says a tenant signature means the PM or owner has to pay whatever he writes on the invoice - doesn't make it legal or binding. 

Last week he sent me an invoice for 3 hours to go pick up some materials that the contractor on the job should have handled.  

@Devin Dang and @Jordan Moorhead are great people to reach out to for this 

If there is a surplus, we provide the tenant with the option of leaving it in the fund (i.e. if winter is approaching and the bills are expected to grow); applying it towards the next month's rent or, if at the end of the lease, refunding it.If there is a deficit, we invoice the tenants and the amount is due at the start of the following month.

For example, if you pay your invoices 14 days late, it will be reported as such.

If they are going to honor your request they can notify you by sending an invoice, or notice of intent to invoice.

Dang, man.  

Very convenient, burns calories, saves gas, and just dang fun!

This includes files such as tenant leases, repair estimates & invoices as well as events such as tenants moving in or out of your property, tenant rent payments & notifications if your account becomes delinquent.

They sent me a price brochure, called them back up to tell them what I wanted, they then send you a checklist and an invoice.