We worked this out with our CPA and this was his recommendation so i recommend starting with 1 account and as you grow and scale talk to your CPA and banker to see what they are seeing other investors do and what they recommend for your situation

My long-term goal is to build a portfolio of multifamily rentals while also working as an agent helping investors scale their portfolios.Your experience sounds incredible!

@River Sava is correct that a LLC makes it easier to scale.

I currently broker LIHTC multi-family for a large firm coast to coast and am also interested in MF in the Arizona submarkets as well, and will eventually invest on that scale - I just figure breaking into the state through SFH flips may be a more risk adverse way to understand the pros and cons to phoenix submarkets.

This property also launched my short-term rental journey, running our first Airbnb before transitioning it to a steady cash-flowing rental, allowing us to scale into bigger projects.

In the next 2 years, I'll be looking to purchase a MFR to househack. with the idea of reinvesting all of the cashflow to help scale.

Quote from @Robert Ruschak: Would you skip the 700+ single family houses and scale up faster into multi-family?

However if you aren't doing mass scale, we definitely suggest letting the contractor handle material purchasing.As long as the client has all of the materials at the jobsite, place them where they go, they are all the correct type/fit and there are all of the misc parts (adapters/special hardware/etc) needed to do the install.

Bonus Tip: If this quadruplex is out of state, I’d highly recommend building a reliable local team (cleaners, handymen, etc.) and maybe consider hiring a co-host or VA to help with day-to-day tasks, especially if you scale up. 

I know you can do one per but that would be a hassle if you scaled your business.