Callsign database

Country Specific - Alphabetical
Australia ACMA register The ACMA provides this lookup for ALL spectrum licence categories in Australia, including hams.

Canada RAC callsign database From Radio Amateurs of Canada (RAC)

Germany (Page in German)

New Zealand RSM databaseRadio Spectrum Management database for ALL spectrum licence categories in New Zealand.

South Africa South African Call Book From the South African Radio League.

USA FCC Data search. lookup page provided by ARRL

Multi Country sites
HamCall Hamcall callsign server. Worldwide server for callsigns

QRZ.COM QRZ Database directory QRZ provides callsign lookup for hams all over the world. To be in their database, you must have registered and provided information.