All guests are informed that this is a first-come type of business, and they have 72 hours to pay the invoice and return all signed paperwork.

I require an immediate email with the description and invoice.  

For helocs the seasoning is 12 months to get the appraised value unless all invoices of the remodel are sent. 

If you pay heat they may have a running invoice for oil/ gas the last year or you could call the gas company for an average. 

If your lease has this, issue an invoice to the 2nd tenant and let them know they are in default and what the next steps will be (e.g. you can file for eviction).I have had residents who pet sit their kids dogs - they pay the non-refundable pet fee and we build the pet rent into the monthly rent.   

Remediation is to take about a week and seller will be providing all invoices and services done, and keep us in as close communication as possible.

Currently our process is to save the cost/invoice in dropbox, then save the number in a seperate exel sheet for the specific job. 

I also provide my owners with scanned copies of all the invoices so they can match it all up themselves. 

Isn't it also common practice to receive an invoice, or something documenting the work that was done to maintain the road?

The tenant is paying for it, so use an outside source and have an invoice.