Only 1 ERO per ProSeries license.

Just making sure ... you are asking about EROs and their EFINs, not tax preparers entering their PTINs, right?

Then ProSeries allows multiple Preparer / ERO profiles under the same firm, each with their own PTIN and ERO PIN, while using the same firm EFIN to sign and transmit returns ?

It allows multiple preparers to each use their own PTIN.  

The IRS wants the ERO Practitioner PIN to be the same all season, so all preparers should be using the same ERO Practitioner PIN.

The ERO is the business at that location, not the individual preparers, which is why it all goes under one ERO.

Thank you