LoTW Files and Icons
LoTW uses four kinds of files, distinguished by Filename Extension. On Windows, Windows Explorer displays these files with an Icon and Type:
| Filename Extension | Icon | File Type | Created By | Usage |
| .tq5 |  |
Callsign Certificate Request | TQSL | Callsign Certificate Request File submitted to ARRL |
| .tq6 |  |
Callsign Certificate | ARRL | Callsign Certificate File referenced and managed by TQSL (cannot be backed-up, recovered, or moved to another PC) |
| .tq8 |  |
Digitally Signed Log | TQSL or logging application | Digitally Signed Log File submitted to LoTW |
| .p12 |  |
Personal Information Exchange | TQSL | Certificate Container File managed by TQSL; can be backed-up, recovered, or moved to another PC |
| .tbk | |
TQSL Backup | TQSL | Backup File created by TQSL that contains all certificates, station locations, and preferences in a form that can be backed-up, recovered, or moved to another PC |