Because when you keep them separate your bank statements are your book keeping.

The biggest part is book keeping and that is outsourced and done in QuickBooks.

If that is the case, QBO will be the software that most bookkeepers and tax professionals are familiar with.

Typically when you end up with significant cashflow or a high number of monthly transactions a bookkeeper or CPA can save a lot of time and make sure things are ticked, tied, and categorized properly.

While you might want to be independent and not wanting to split commissions, you will also have to pay for all legal advice, accountants, bookkeeping, Error and Omission Insurance, office space, the cost of running an office, etc.

Once you own a certain number of units, you probably need to outsource your bookkeeping anyways.

Things like bookkeeping, inspections, decorating, tenant approval and screening, repairs, advertising, paying taxes, etc.

Your bookkeeping will be more complex though.Do you have access to a Line of Credit - either primary residence or for your LLC? 

But I did the bookkeeping, payroll, applied for workman's comp and unemployment insurance myself.

My CPA is not adding clients right now but my bookkeeper does peoples taxes as well and she could totally handle a portfolio like yours.