Below are a few common tax preparer acronyms that are used when referring to preparer information:
ERO (Electronic Return Originator) - Would be the tax preparer. The origination of the prepared electronic tax return. If you prepared the return and electronically filed it, you would be the ERO.
EFIN (Electronic Filing Identification Number) - This (often) six digit number is the identification number for your filing office as a whole. This number is given by the IRS and must be applied for as well as maintained. To learn more about this application process, visit the following IRS.gov link: https://www.irs.gov/e-file-providers/become-an-authorized-e-file-provider
PTIN (Preparer's Tax Identification Number) - Anyone who prepares or assists in preparing federal tax returns for compensation must have a valid PTIN before preparing returns. All enrolled agents must also have a valid PTIN. To learn more about application requirements for a PTIN, visit the following IRS.gov page: https://www.irs.gov/tax-professionals/ptin-requirements-for-tax-return-preparers
Practitioner PIN - This is a PIN that the preparer fabricates for the use of electronically signing returns using a PIN. This PIN cannot begin with 0, nor can it be all 0's.