Unless he is giving you the actual invoices to pay yourself ( how i do it )  Myself we pay all invoices and GC gets a set fee and a profit bonus.. 

How I have it set up currently is the owners (my clients) are receiving Airbnb payouts and I send an invoice at the end of the month for my Mgmt fee.

Also, is an invoice from this person enough a record for tax purposes or do we need a receipt of a payment from him?

After some threshold of these nuisance calls the landlord will begin receiving invoices from the City and will then be forced to deal with the tenant.

Once a qualified tenant is placed, maintenance is the bulk of what happens when managing properties so you want to make sure that they have policies in place for taking maintenance calls, handling invoices or payments, and following up with the work.

Then we address those issues with my Handyman that will give me his paid invoice showing all work was done.

They also take too long to pay their invoices, and on top of that they deduct 10% from the payment to us for "commission". 

Here's a PARTIAL list:Office rentComputers, printers & softwareInternet & phone billOffice furnitureOffice supplies: paper, postage, ink, etc.Office liability insuranceAuto expenses: monthly payment, insurance, gas, maintenance, registration/plate feesBroker license fees: annual, monthly board & MLS fees, continuing education fees, E&O insuranceEquipment: lockboxes, signs, etc.Payroll & payroll taxesBusiness income tax preparation and paymentsLabor: answering phones, calling past due tenants, scheduling tours, taking marketing pics, processing those pics, writing ads, researching rent amounts, posting ads, explaining to owners how rent determined & showing where ad posted, opening & processing mail, posting payments, bank deposits, scanning documents & posting to owner & tenant portals, explaining accounting to owners so they understand their monthly statements, taking pics/videos of repairs, finding reputable handymen and contractors, confirming they're properly licensed & insured and tracking annually, verifying repairs done properly, processing invoices for utility bills, repairs, taxes, city inspections, scheduling periodic property evaluations/inspections with tenants that don't want strangers in their homes, explaining to owners why taking so long, and more & more & more...

Hi Bob,Make sure to have an investor friendly realtor so that you won't have issues afterwards.HOA are very tricky, as the boards change very often, they could be years that they don't do much and other years that they are suing residents if they are not maintaining the lawn.CC&R are the key to review in this case, those are public so available for you, and those are required to be provided by the seller every time.Don't go the route of do it anyways, that will have cause you consequences, I had a time that the HOA sued a property owner just for missing 6 months (the property owner was renting out the property and it didn't receive the invoice to pay the dues so she forgot).

I’d use it to get into a lease and use it as some operating capital until the first invoice gets paid.