If you’ve forgotten the combination to a Master Lock combination lock, you have a few options. If the lock isn’t locked onto anything, you can make a photocopy of the serial number and send that into Master Lock for the combination. If, however, your lock is attached to something, you can break the lock, call a locksmith, use a shim, or figure out the combination. Of these options, only the last will leave you with a usable lock without emptying your wallet. Unfortunately, there are 64,000 possible combinations on a standard 40-number Master Lock. With this method, however, you can quickly narrow that down to 100 combinations, a workable number to try if you’ve got the time and the inclination to give it a shot.