United States · Tax preparer identifiers
PTIN validator.
Check that a Preparer Tax Identification Number has the format the IRS publishes: a capital P followed by eight digits.
The rule in one line: the letter P, then exactly eight digits, and those eight digits cannot be all zeros or all nines. Example shape: P01234567.
How to check a PTIN
- Type or paste the value. Spaces and hyphens are ignored and case does not matter.
- Press Check.
- Read the result: either the normalized value, or the exact rule it breaks.
Your input stays on your device
The check runs in your browser, inside an isolated frame on this page that has no network access. Nothing you type is uploaded to TNAADO or anyone else, and nothing is stored. The advertising on this page sits outside the frame and cannot see what you enter.
How the PTIN format works
A Preparer Tax Identification Number (PTIN) is the number that paid tax return preparers put on the returns they prepare. The Internal Revenue Manual (IRM 3.11.23) says a PTIN "begins with the alpha P followed by an eight-digit number" and instructs reviewers to treat an SSN or PTIN that is all zeros or all nines as invalid. Those are the only rules this page applies.
The common mistakes it catches are a missing leading P, a letter O typed where the digit zero belongs, a transposition that drops or adds a digit, and placeholder values such as P00000000 or P99999999. It deliberately does not look the number up. The IRS page on PTIN requirements points to the online PTIN system for account holders and to Form W-12 for paper applications, and the renewal and fee details change over time, so check the IRS page for current figures.
Because a PTIN identifies an individual preparer, this tool runs inside an isolated frame with no network access. Nothing you type is sent or stored.
Worked example (made-up value): P01234567 starts with P and has eight digits, not all the same, so it passes. 01234567 fails (no P). P0123456 fails (seven digits). P0123456O fails because the last character is the letter O. P99999999 fails as all nines.
Method
The check is a fixed set of format rules applied to the text you type, after upper-casing it and removing spaces and hyphens. There is no database, no estimate and no assumption about who you are: the same input always gives the same answer, and every rule is traceable to the sources below.
What this does not cover
- Whether the PTIN was issued, is current for the year, or belongs to the preparer named on a return.
- Any check digit: the sources checked do not publish one, so none is verified.
- Other preparer credentials (CPA licence, Enrolled Agent number, CAF number).
- Whether a preparer is permitted to prepare a particular return.
Frequently asked questions
What does a PTIN look like?
The letter P followed by eight digits, for example P01234567 (a made-up value).
Is a PTIN the same as an SSN or EIN?
No. It is a separate identifier for paid preparers. The IRM does, however, apply the same all-zeros and all-nines invalidity test to an SSN or PTIN.
Can I verify a preparer with this tool?
No. It only checks the format. The IRS publishes a directory of federal tax return preparers on irs.gov.
Is anything I enter stored?
No. The check runs in your browser inside a sandboxed frame with no network access.
Sources
- IRS, Internal Revenue Manual 3.11.23 (PTIN format and invalid values) (retrieved 2026-10)
- IRS, PTIN requirements for tax return preparers (retrieved 2026-10)
Shape only
A correctly formatted value is not proof that an identifier was issued, is active or belongs to the person or business in front of you. Confirm with the issuing agency. This page is general information, not legal, tax or compliance advice.