Invalid Call Sign Requests

Last updated Thursday, July 10, 2025 5:50:25 AM (Arizona)
Thursday, July 10, 2025 12:50:25 PM (UTC)

Applications

Invalid Call Signs

This page shows the FCC guidelines for calls which are not available for requesting on an FCC application followed by the invalid call signs which have been requested in the last month and the rule they are in violation of.

The following call signs are not available for assignment and therefore any request for call signs in the following categories are invalid and will be denied.

  1. KA2AA-KA9ZZ, KC4AAA-KC4AAF, KC4USA-KC4USZ, KG4AA-KG4ZZ, KC6AA-KC6ZZ, KL9KAA- KL9KHZ, KX6AA-KX6ZZ;
  2. Any call sign having the letters SOS or QRA-QUZ as the suffix;
  3. Any call sign having the letters AM-AZ as the prefix (these prefixes are assigned to other countries by the ITU);
  4. Any 2-by-3 format call sign having the letter X as the first letter of the suffix;
  5. Any 2-by-3 format call sign having the letters AF, KF, NF, or WF as the prefix and the letters EMA as the suffix (U.S Government FEMA stations);
  6. Any 2-by-3 format call sign having the letters AA-AL as the prefix;
  7. Any 2-by-3 format call sign having the letters NA-NZ as the prefix;
  8. Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs);
  9. Any 2-by-3 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9;
  10. Any 2-by-2 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9;
  11. Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9;
  12. Call signs having the single letter prefix (K, N or W), a single digit numeral 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and a single letter suffix are reserved for the special event call sign system.
Call SignRule Violation
 A2MALCall does not fall within a valid group as per FCC Guidelines
 A2MS Call does not fall within a valid group as per FCC Guidelines
BR3BABCall does not fall within a valid group as per FCC Guidelines
BR7BABCall does not fall within a valid group as per FCC Guidelines
CK4A  Call does not fall within a valid group as per FCC Guidelines
CK4D  Call does not fall within a valid group as per FCC Guidelines
CK4P  Call does not fall within a valid group as per FCC Guidelines
CK4Z  Call does not fall within a valid group as per FCC Guidelines
CL4A  Call does not fall within a valid group as per FCC Guidelines
CL4D  Call does not fall within a valid group as per FCC Guidelines
CL4P  Call does not fall within a valid group as per FCC Guidelines
CL4Z  Call does not fall within a valid group as per FCC Guidelines
 D4TA Call does not fall within a valid group as per FCC Guidelines
EM4JFHCall does not fall within a valid group as per FCC Guidelines
KP6K  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP6R  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP6X  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP7K  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP7R  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP7X  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP8K  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP8R  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP8X  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP9K  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP9R  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9
KP9X  11.  Any 2-by-1 format call sign having the letters KP, NP or WP as the prefix and the numeral 0, 6, 7, 8 or 9