The biggest problem is when you have to evict tenants from the legal units, the tenant lawyer, usually "Legal Aid"  will find your illegal unit, demand the eviction be halted till you evict the tenant in the illegal unit first, and normally the court will go along with that.The funniest thing I heard was in an election campaign years ago, Mayor Koch was asked by a reporter what he plans to do about all these illegal apartments, and if he knew how many there are.

Don't skimp out or try to get it band aided cheaply. 

@Dwight CookI second the comment to just rip the band aid of its easy to rent the units If it's not so easy raise em all a little and push the very low units closer to realityThis should mitigate losing a few tenants at once while moving you closer to your goal of market ratesI've had success with a 2 year plane to take a smaller financial loss of rent potential while avoiding high vacancy and all the effort to replace a good tenant.

Separate book sand records are maintained to reflect income and expenses for each rental RE enterpriseNote: A separate real estate enterprise may constitute multiple properties as long as all commerical or all residential as noted above4. 250 or more hours of rental services are performed for the enterprise (see detail below)5.

I live in Arizona and we just got under contract on a house in Enterprise, AL, so we definitely need to hire out, and that seems like a great way to get it done.

Bellwether Enterprise is a good lender to work with

I have been looking at several options and have not found a one stop shop that covers everything I am looking for and fits the criteria for cloud based and easy collaboration.The accounting/finance end of our business is managed in house with an enterprise level accounting software.

However, once you get in the game, you will realize that finding deals is the hardest part of the entire enterprise.

I've used my STR host knowledge to aid in our traveling. 

As a LL, you have a big target on your back...you are offering costly goods and services to the Public, THEY will often be the ones that hold YOUR feet to the fire...with free legal aid and advocates.If you do not already understand the fundamental systems in your property, you will have expensive learning sessions with plumbers, electricians, HVAC people, carpenters and installers.