How to Find the Combination of a Master Lock Using Its Serial Number

A Master Lock is a type of padlock, and older combination Master Locks feature a serial number. Master Lock quit printing serial numbers on new locks in 2009. The company still manufactures this type of lock; however, the locks no longer have serial numbers. If you lost the combination to your Master Lock and your lock has a serial number, you can find the combination for your lock by sending a form to Master Lock. You can not reset the combination on this type of Master Lock. On Master Locks with resettable dials, if you lose the the combination, it is not possible to find the lost combination.

Print the Master Lock lost combination form. You can find a copy of the Master Lock lost combination form on its website. The form is a PDF document you can print on your computer.

Print your name, Master Lock serial number and return address on the form.

Take the form to a notary public. Make sure you sign the form in the presence of the notary and have the notary sign and notarize the form. Master Lock requires you to notarize the form to verify your identity.

Make a photocopy of the back of the Master Lock. The photocopy must clearly display the lock's serial number. Although not required, you should also make a copy of the form you took to the notary for your records.

Mail the completed and notarized lost combination form and the photocopy to: Master Lock Warehouse, 1600 W. La Quinta Rd, Suite/WHSE # 1, Nogales, AZ 85621. You can expect to receive the combination in four to six weeks.


  • Newer Master Locks do not have serial numbers. You can not use the Lost Combination Form if your Master Lock does not have a serial number.