Invalid Call Sign Requests

Last updated Thursday, October 22, 2026 5:53:40 AM (Arizona)
Thursday, October 22, 2026 12:53:40 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
 A5MAWCall does not fall within a valid group as per FCC Guidelines
AA0AAT6.  Any 2-by-3 format call sign having the letters AA-AL as the prefix
AC4RES6.  Any 2-by-3 format call sign having the letters AA-AL as the prefix
AT0AAT3.  Any call sign having the letters AM-AZ as the prefix (these prefixes are assigned to other countries by the ITU)
AZ6ZO 3.  Any call sign having the letters AM-AZ as the prefix (these prefixes are assigned to other countries by the ITU)
DR8GONCall does not fall within a valid group as per FCC Guidelines
K1GIRLCall sign is incorrectly formatted as per FCC Guidelines
 K1QTE2.  Any call sign having the letters SOS or QRA-QUZ as the suffix
 K1QTZ2.  Any call sign having the letters SOS or QRA-QUZ as the suffix
NIAIUCall sign is incorrectly formatted as per FCC Guidelines
NIUGCall sign is incorrectly formatted as per FCC Guidelines
NJ5MSL7.  Any 2-by-3 format call sign having the letters NA-NZ as the prefix
NJ5WSH7.  Any 2-by-3 format call sign having the letters NA-NZ as the prefix
NL4FFN7.  Any 2-by-3 format call sign having the letters NA-NZ as the prefix
NL4FIN7.  Any 2-by-3 format call sign having the letters NA-NZ as the prefix
 R4AWRCall does not fall within a valid group as per FCC Guidelines
 R4MBOCall does not fall within a valid group as per FCC Guidelines
W4D556Call sign is incorrectly formatted as per FCC Guidelines
W4DVLK9Call sign is incorrectly formatted as per FCC Guidelines
W4JRHDCall sign is incorrectly formatted as per FCC Guidelines
W4T556Call sign is incorrectly formatted as per FCC Guidelines
W4T762Call sign is incorrectly formatted as per FCC Guidelines
WK4OFF8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
WM4OFF8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
WR0CAR8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
WR1CAR8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
WR3CAR8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
WR4OFF8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
WR5CAR8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
WR7CAR8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
WT4OFF8.  Any 2-by-3 format call sign having the letters WC, WK, WM, WR, or WT as the prefix (Group X call signs)
ZR4MBOCall does not fall within a valid group as per FCC Guidelines