You must apply for a new Electronic Filer Identification Number (EFIN) when your tax preparation business structure has changed in these ways:
- You obtain a new Employer Identification Number (EIN).
- The business is a sole proprietorship and the owner dies.
- You have a new location from which you will be transmitting returns. (Each location must have its own EFIN.)
Note that EFINs cannot be bought and sold, rented, leased, or transferred. You also cannot obtain an EFIN by purchasing a package deal that includes it.