EFINs, ETINs and Password
Providers must protect their EFINs, ETINs and passwords from unauthorized use. Providers must never share the numbers and passwords with others including not transferring EFINs or ETINs to another entity when transferring the business by sale, gift or other disposition. If the IRS learns of a compromised EFIN or ETIN, we will change the number and notify the Provider by mail.
The IRS mails a security letter to Transmitters, Software Developers and Online Providers containing a replacement password when necessary. The last two digits of the corresponding Electronic Transmitter Identification Number (ETIN) are in the letterhead.
All Providers must include their identification numbers with the electronic return data of all returns it transmits to the IRS. If more than one Authorized IRS e-file Provider is involved in the origination and transmission of the return data, applicable electronic filing identification numbers (EFIN and ETIN) for each Provider must be included in the electronic return record. Online Providers must include an EFIN with a Prefix Code of 10, 21, 32, 44 or 53 with each Online Return.