United States · FCC identifiers
FCC FRN validator.
Check that an FCC Registration Number has the format set out in the FCC's rules: a 10-digit number.
The rule in one line: an FRN is a 10-digit number. This tool accepts spaces and hyphens, then requires exactly ten digits.
How to check a FRN
- 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.
What an FRN is
The FCC Registration Number (FRN) is defined in 47 CFR 1.8001(a) as "a 10-digit unique identifying number that is assigned to entities doing business with the Commission." Under paragraph (b) it is obtained through the Commission Registration System (CORES) on the FCC website or by filing FCC Form 160. Licensees, filers and anyone paying fees to the FCC deal with FRNs constantly, and the most common data-entry fault is a spreadsheet that strips leading zeros and turns a 10-digit number into a 9- or 8-digit one.
That is the situation this checker is built for. It strips spaces and hyphens, rejects anything containing letters or symbols, and requires exactly ten digits. When the count is short it reminds you to restore a dropped leading zero, which is a typing fix rather than a claim about what the FCC will accept in every system.
A passing result only means the text is shaped like an FRN. It does not tell you whether the number was issued, whose it is, or whether it is in good standing for fees or red-light purposes.
Worked example (made-up value): 0012345678 is ten digits, so it passes. 12345678 fails: eight digits, which is what a spreadsheet leaves behind after stripping two leading zeros. 001234567A fails because of the letter.
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 FRN was assigned, who holds it, or its CORES status.
- Whether licences, call signs or fees are attached to it.
- Any check digit: none is published in the rule checked, so none is verified.
- Other FCC identifiers such as a FCC ID, call sign or license number.
Frequently asked questions
How many digits is an FCC FRN?
Ten. 47 CFR 1.8001(a) defines it as a 10-digit unique identifying number.
Where do I get an FRN?
Through the Commission Registration System (CORES) on the FCC website, or by filing FCC Form 160, per 47 CFR 1.8001(b).
My FRN has only 8 digits after copying from a spreadsheet. Why?
Spreadsheets often drop leading zeros. Pad on the left to ten digits and compare with the original source.
Does this check CORES?
No. It checks the format only and never contacts the FCC.
Sources
- 47 CFR 1.8001 – FCC Registration Number (FRN) (retrieved 2026-10)
- FCC, Commission Registration System (CORES) (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.