What is .UNL file extension?
Backup file created by MapSource, a program used to manage maps for Garmin navigational devices; contains unlock codes for maps; used as a backup copy so that the codes can be restored back to the Garmin device.
To create a UNL file in MapSource, select Utilities ? Unlock Maps, click "Next," and choose "Backup my unlock codes to a file." To reload unlock codes, select Utilities ? Unlock Maps, click "Next," select "Retrieve and reinstall all my unlock codes, click "Next," and then select "Retrieve my unlock codes from a file on my PC."
NOTE: Unlock codes are specific to a single GPS unit purchased from Garmin. Therefore, it is not possible to use a UNL file to unlock maps on multiple Garmin devices.
You can see a list of software programs here on www.easyfileopener.org that can open this file type so that you don’t need to search for it on the web. You can then open your file with this extension using a software listed below.