I myself have three rentals, and I can tell you based on my own experience that there's no need to open a business account. It doesn't make sense, because with few exceptions a business account is not free. You have to pay for each transaction you run through that account. Additionally, a business account doesn't pay interest. (ignoring the fact that interest on a savings or checking account is less than 1% these days.)
I myself just have a regular personal checking account that I use only for the rental property. All rental income is deposited to that account, and all rental expenses are paid from that account. I don't use the account for anything else what-so-ever, with no exceptions.
Once a month I'll write a check to myself for my "owner's draw", and that particular transaction is the only one each month that is not tax deductible. All other withdrawals from that account are a rental expense that can be claimed as such on the SCH E.
Having a personal checking account for the rental properties makes tracking all rental income and expenses a breeze, not to mention it makes my life much easier at tax time.
Finally, since it's a "regular" personal checking account, I don't have to pay any BS transaction fees every time I write a check, use the debit card to pay an expense, or deposit a rental payment.
