Hi and welcome to our site!Your friend is required to use the same PTIN.He may not have several PTINs.
so basically he is not subject to only one EFIN or company EIN. Is it correct? thanks
That is correct - EIN represents a business entity. If there are two entities - they use two different EIN.However for PTIN purposes - only one may be used when tax returns are signed by the same preparer.
Correspondingly - EFIN identifies an Authorized IRS e-file Provider.If two different e-file providers are used - there should be two different EFINs.