Why is the ITIN format the same length as an SSN?

Both numbers use the 9-digit, 3-2-4 layout so IRS systems can process them interchangeably on tax forms. The IRS reserved the leading digit 9 for ITINs while the SSA leaves it unused, which keeps the two numbers visually identical but programmatically distinct.

Which middle digits are valid in the ITIN format in 2026?

Four valid ranges: 50-65, 70-88, 90-92, and 94-99. ITINs with middle digits 70 through 88 have been deactivated under the IRS rolling expiration program and must be renewed before use on a tax return.

Does the ITIN format ever include letters or special characters?

No. The ITIN format contains only digits and two hyphens. Any number with letters, spaces, or non-hyphen punctuation is not a valid ITIN.

How can I tell an ITIN format from an EIN format?

An EIN is also 9 digits but uses a 2-7 grouping (XX-XXXXXXX). An ITIN uses a 3-2-4 grouping (9XX-XX-XXXX) and always starts with 9. The hyphen position is the fastest visual cue.

Updated June 24, 2026

ITIN Number Format: The 9-Digit Structure Explained

What Is the Exact ITIN Number Format in 2026?

The IRS issues every Individual Taxpayer Identification Number in the same 9-digit format: 3 digits, hyphen, 2 digits, hyphen, 4 digits. The first digit is locked at 9. The middle pair encodes the assignment cohort. The trailing 4 digits are sequential within that cohort and act as a unique serial.

Canonical ITIN format:

9XX-XX-XXXX

Position 1: always 9 · Positions 2-3: cohort prefix · Positions 4-5: assignment range · Positions 6-9: serial.

How Does the ITIN Format Break Down Position by Position?

Position	Allowed Values	Purpose
Digit 1	9	IRS-reserved ITIN indicator
Digits 2-3	0-9	Cohort identifier
Digits 4-5	50-65, 70-88, 90-92, 94-99	Assignment range (distinguishes ITIN from SSN)
Digits 6-9	0-9 sequential	Unique serial within cohort

For format samples that match these rules, see the ITIN number example page.

Why Is the ITIN Format Designed This Way?

The 9-digit, 3-2-4 layout matches the SSN layout deliberately. IRS systems, tax-prep software, employer payroll systems, and state licensing systems all expect 9 digits with the same hyphen pattern. Mirroring the format means ITINs can be processed on existing forms (W-2, W-9, 1099, 1040) without parallel software changes.

The leading 9 plus the reserved middle-digit ranges keep the two number types programmatically distinct, so banks and lenders can apply ITIN-specific rules without ambiguity. See the full explanation of why ITINs start with 9.

How Has the ITIN Format Changed Since 1996?

The 9-digit layout has never changed. What has changed is the set of valid middle-digit ranges. The IRS originally used 70-88 as the primary range, then added 90-92 and 94-99 to expand capacity. Range 50-65 was added in 2013. Middle digits 70-88 were retired in phases between 2016 and 2020 under the rolling expiration program mandated by the Protecting Americans from Tax Hikes (PATH) Act of 2015.

How Does the ITIN Format Compare to SSN and EIN Formats?

Number	Format	Leading Digit
ITIN	9XX-XX-XXXX	9
SSN	XXX-XX-XXXX	0-8
EIN	XX-XXXXXXX	0-9

Full comparison details live on ITIN vs SSN and ITIN vs EIN.

Frequently Asked Questions About the ITIN Number Format

The ITIN number format is 9XX-XX-XXXX: 9 digits printed in a 3-2-4 pattern. The first digit is always 9. The middle two digits fall within 50-65, 70-88, 90-92, or 94-99. The final 4 digits are sequential within each cohort.

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