When it comes to a return with multiple rental properties, there are some limitations when E-Filing. Currently, the limit is a maximum of 15 Sch. E forms (including Sch E Dup) with a total of 45 properties. While there is a limit for sending a return electronically, there is no limit for how many can be in the actual return. Just know that anything past the limit stated above would cause the return to have to be mailed to the IRS or state agency by US Mail.