Electronic Filling Identification Number (EFIN) Policies and Procedures

IRS e-file providers must abide by the policies and procedures in Publication 3112, IRS e-file Application and Participation, and Publication 1345, Handbook for Authorized IRS e-file Providers of Individual Income Tax Returns.

Providers are required to protect their EFINs and passwords from unauthorized use, and should never share them. This includes accepting payment for the use of an EFIN (for example, renting, leasing, or purchasing) and/or transferring EFINs to another entity when transferring the business by sale, gift or other disposition. In addition, when providers resell software, they cannot include their EFIN. Read more here.