Invalid Call Sign Requests

Last updated Tuesday, April 21, 2026 5:53:20 AM (Arizona)
Tuesday, April 21, 2026 12:53:20 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
 A6LB Call does not fall within a valid group as per FCC Guidelines
 B6LB Call does not fall within a valid group as per FCC Guidelines
 C6LB Call does not fall within a valid group as per FCC Guidelines
 D6LB Call does not fall within a valid group as per FCC Guidelines
 F6LB Call does not fall within a valid group as per FCC Guidelines
 F9LB Call does not fall within a valid group as per FCC Guidelines
 G6LB Call does not fall within a valid group as per FCC Guidelines
 G9LB Call does not fall within a valid group as per FCC Guidelines
 H6LB Call does not fall within a valid group as per FCC Guidelines
 H9LB Call does not fall within a valid group as per FCC Guidelines
KAAMCall sign is incorrectly formatted as per FCC Guidelines
KMAACall sign is incorrectly formatted as per FCC Guidelines
KMAA73Call sign is incorrectly formatted as per FCC Guidelines
KNIQCall sign is incorrectly formatted as per FCC Guidelines
KNIQ73Call sign is incorrectly formatted as per FCC Guidelines
KNIQUECall sign is incorrectly formatted as per FCC Guidelines
KP7CAT9.  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
 L9LB Call does not fall within a valid group as per FCC Guidelines
 M6LB Call does not fall within a valid group as per FCC Guidelines
 M9LB Call does not fall within a valid group as per FCC Guidelines
 P6LB Call does not fall within a valid group as per FCC Guidelines
 P9LB Call does not fall within a valid group as per FCC Guidelines
 R6LB Call does not fall within a valid group as per FCC Guidelines
 R9LB Call does not fall within a valid group as per FCC Guidelines
 S9LB Call does not fall within a valid group as per FCC Guidelines
TF0DM Call does not fall within a valid group as per FCC Guidelines
TF0DRMCall does not fall within a valid group as per FCC Guidelines
TFODMCall sign is incorrectly formatted as per FCC Guidelines
TFODRMCall sign is incorrectly formatted as per FCC Guidelines
TST5DMCall sign is incorrectly formatted as per FCC Guidelines
TSTDM5Call sign is incorrectly formatted as per FCC Guidelines
 V6LB Call does not fall within a valid group as per FCC Guidelines
 V9LB Call does not fall within a valid group as per FCC Guidelines
WMAACall sign is incorrectly formatted as per FCC Guidelines
WNIQUECall sign is incorrectly formatted as per FCC Guidelines