EIN Number Format: What the 9 Digits Mean

What does a valid EIN look like?

A valid EIN reads XX-XXXXXXX: for example 12-3456789 or 04-1234567. It contains exactly 9 digits, 1 hyphen after the 2nd digit, and no letters.

The IRS assigns the number under 26 U.S.C. § 6109, which requires an identifying number on every federal return, and 26 CFR § 301.6109-1 names the EIN as the identifying number for entities. The 7 digits after the hyphen are a sequence, not a code: they carry no information about the entity type, the state of formation or the year of issue. Nothing in the format tells a reader whether the holder is an LLC, a corporation, a trust or a sole proprietor.

Forms and databases strip the hyphen. A W-9 box, a payroll system and the SEC EDGAR filing header all hold the same number as 9 bare digits, so 123456789 and 12-3456789 are 1 EIN. Add the hyphen back after the 2nd digit when you type it onto a government form; the IRS instructions for Form SS-4 show the hyphenated form.

What do the first 2 digits of an EIN mean?

The first 2 digits identify the IRS campus that assigned the number, or show that the application was filed through the online EIN Assistant. The IRS publishes the full list; it is reproduced below as published.

Source: IRS, How EINs are assigned and valid EIN prefixes, page reviewed 2026-04-09 [1].

Several prefixes appear under both Philadelphia and the internet route (33, 39, 41, 42, 46, 85, 86, 87, 88, 92, 93, 99); the IRS lists them in both rows. Counting each prefix once, 83 two-digit prefixes are valid. The remaining 17 (00, 07, 08, 09, 17, 18, 19, 28, 29, 49, 69, 70, 78, 79, 89, 96, 97) do not appear on the list and have never been issued, so a number beginning with 1 of them is not an EIN the IRS assigned.

The prefix is history, not geography. A business formed in Texas and filed online carries an internet prefix such as 81 or 88, and a trust whose Form SS-4 was faxed in 2004 carries whichever campus processed faxes that year. Prefix 31 is the exception with a meaning: it is reserved for numbers issued through the Small Business Administration.

How does the EIN format compare with an SSN, ITIN and PTIN?

Four IRS-recognised identifying numbers share 9 characters but differ in grouping and first character. The 2-7 grouping is unique to the EIN; the 3-2-4 grouping belongs to numbers issued to people.

Sources: IRS, Taxpayer Identification Numbers (TIN); IRS, Individual Taxpayer Identification Number [5], [6].

The grouping is the fastest tell. Two digits, a hyphen, seven digits: an entity. Three, two, four: a person. A Form W-9 asks for 1 of the 2 and the box the signer fills in says which. Read the full comparison on the EIN vs SSN page, the EIN vs ITIN page, and the EIN vs TIN page.

How do you check whether an EIN is valid?

Three checks in order: shape, prefix, then a match against IRS records. Only the 3rd proves the number belongs to the name beside it, because the IRS publishes no check digit for an EIN.

Repeated digits (99-9999999) and runs (12-3456789) pass checks 1 and 2 and fail check 3; they are the 2 placeholder patterns most often typed into a form by someone who did not have the real number. For your own EIN, the IRS Business and Specialty Tax Line, 800-829-4933 (Monday-Friday, 7 a.m. to 7 p.m. local time), confirms it by issuing a Letter 147C; the steps are on the 147C letter page. For a vendor’s EIN, the verify an EIN number page walks through TIN Matching and the W-9 flow.

Where does the EIN appear, and in which format?

The same 9 digits print on 8 common documents, hyphenated on IRS paper and stored without the hyphen in most databases. The CP-575 is the first place it appears and the 147C is the replacement.

Private companies appear on none of the public rows: no IRS database lists their EINs, and the SEC header covers only companies that file with the SEC. How to find a number you do not hold is covered on the EIN lookup page and the EIN search by company name page.

What if you have no EIN yet?

The IRS issues one for $0: in 15 minutes online for applicants with an SSN or ITIN, or in 4 business days by fax with the word Foreign on Form SS-4 line 7b for applicants with neither.

ein-number.com prepares and files the Form SS-4 for $69 (Standard) or $99 (Fast, filed within 24 hours), with a second reviewer checking every line before the IRS sees it and a full refund if an error on our side causes a rejection. Applicants who hold an SSN or ITIN lose nothing by filing at irs.gov themselves.

What else do people ask about the EIN number format?