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Electronic Filing Identification Number (EFIN): An EFIN is required by a tax provider to file a returna nine-digit number assigned by the Internal Revenue Service (IRS) to businesses and other entities that allows them to file taxes.
Employer Identification Number (EIN): An EIN is a unique number assigned to a business so that the IRS can distinguish one business from another.
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Submission ID: A unique number assigned to electronically filed tax returns so the IRS can distinguish between returns. The format is as follows: EFIN, year return was sent, Julian date, and the last 7 digits are assigned based around the time the return is sent.
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