EFINs may cover more than one fixed location to collect data and prepare returns, but cannot be used to initiate electronic transmissions from multiple locations.

According to IRS Publication 3112:

"Providers may need to submit new IRS e-file Applications when expanding their e-file businesses to new business locations. EROs must submit new applications for additional fixed locations from which the origination of the electronic submission of returns will occur. A separate EFIN is required for each fixed location that originates electronic submission of returns. A fixed location is an office owned or leased by the ERO.

For additional locations, owned by the Provider, where the ERO does not originate the electronic submission of returns, the EFIN of the owner’s fixed location can be used. For example, if tax returns are prepared or collected at a location owned by the same Provider, but forwarded to another location for origination of the electronic submission, a new application is not required for the location where the tax returns are prepared or collected."

An "other than fixed" location would represent a mobile preparer, such as one who travels to a taxpayer's home to prepare the return.

If a preparer has a "fixed" location, the EFIN would need to be assigned to that location. Otherwise only data collection and tax return preparation may occur there. The preparer could not transmit a return from a fixed location without an EFIN.

An EFIN should not be used at more than one fixed location, e.g., the one to which it was assigned by the application process. For example, if a preparer has 15 offices and plans to transmit returns from all of them, the preparer would need to have 15 EFINs.