Invalid Call Sign Requests

Last updated Thursday, March 12, 2026 5:55:44 AM (Arizona)
Thursday, March 12, 2026 12:55:44 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
CREA8Call sign is incorrectly formatted as per FCC Guidelines
FASTFN03Call sign is incorrectly formatted as per FCC Guidelines
FN0385Call sign is incorrectly formatted as per FCC Guidelines
FSTFN3Call sign is incorrectly formatted as per FCC Guidelines
 K0X  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.
KBANCall sign is incorrectly formatted as per FCC Guidelines
KBAN69Call sign is incorrectly formatted as per FCC Guidelines
KREA8Call sign is incorrectly formatted as per FCC Guidelines
N0HACKCall sign is incorrectly formatted as per FCC Guidelines
N3Y3Call sign is incorrectly formatted as per FCC Guidelines
N43RLPCall sign is incorrectly formatted as per FCC Guidelines
NI5ENA7.  Any 2-by-3 format call sign having the letters NA-NZ as the prefix
 P1NG Call does not fall within a valid group as per FCC Guidelines
 S7EVECall does not fall within a valid group as per FCC Guidelines
ST3PHNCall does not fall within a valid group as per FCC Guidelines
ST3VENCall does not fall within a valid group as per FCC Guidelines
W5W0Call sign is incorrectly formatted as per FCC Guidelines
WK6KTF8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
WN44LCall sign is incorrectly formatted as per FCC Guidelines
WT4SAM8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
WT6KTF8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)