Reset & Retrieve Lost Combinations

I've lost or forgotten the combination to my Master Lock lock. What can I do?

Does your Master Locklock have a serial number? If it doesn't, we won't be able to help you find your combination because we don't have a record of it. Learn how to find your lock's serial number.

If your lock has a serial number, you can recover your combination in one of three ways. You can visit a Master Lock Distributor / Retailer or submit a Lost Combination form.

Distributor / Retailer

  1. Bring your lock to the retailer. Be sure that it is not attached to anything. If you do not bring the lock, or it is attached to something, we will not release the combination.
  2. Ask them to contact us on your behalf. US distributors can call 1-800-308-9244. Canadian distributors can call 1-800-227-9599.
  3. Please note that although Master Lock does not charge for this service, the retailer may charge a fee.

Submit a Lost Combination Form

  1. Find your lock's serial number.
  2. Print out the Lost Combination Form (PDF).
  3. Have the form notarized by a Notary Public to prove you are the owner of the lock. You can include up to 6 combinations on one notarized form.
  4. Submit your form to:
    Master Lock Warehouse
    24 North Free Port Drive
    Nogales, AZ 85621

Once we receive your request, you will receive your combination in approximately 4-6 weeks.

Send a Photo Via Contact Form

  1. Send a picture of the lock clearly showing it is not attached to anything The image should clearly show the entire lock and the serial number. The lock cannot be attached to anything. Any photo with digital edits will be rejected.
  2. Use the "Contact Us" form to send us the photo. Fill out the form and be sure to select "Lost Combination" option.

We will respond in 7-10 days.

Note: If you are an inmate in a correctional facility, you must submit your request on official prison facility letterhead. In lieu of notarization, the Lost Combination Form must be signed by a prison facility official.

I lost the combination to my Master Lock Set-Your-Own Combination lock. Can you help me reset it?

Unfortunately no. You cannot reset this lock without knowing the current combination. You'll likely need to purchase a new lock.

I accidentally reset the combination on my Master Lock resettable combination lock. Now I don't know the correct combination. Can I reset the lock back and assign a new combination?

Unfortunately, you cannot reset this lock without knowing the current combination. You'll likely need to purchase a new lock.

I've lost the Master Lock reset tool for changing the combination on my lock. How can I get a new one?

As a courtesy, Master Lock customer solutions group can issue you a replacement tool free of charge. You will need to supply the model number or an image of your lock. Please contact us to submit your request.

How can I retrieve my lost combination when my Master Lock lock is attached to a bike, cabinet, locker, or something else?

We will not provide lost combinations if the lock is attached to anything.

I'm unable to get a legible photocopy of my lock for the Lost Combination Form. What should I do?

Try lightening the copy as much as possible. The most important thing is that we can see that the lock is not attached to something.

How do I set the combination on my Master Lock 5400D / 5401D Key Safe?

To set or reset the combination on your Master Lock 5400D / 5401D Key Safe:

  1. Open the compartment door by entering the combination. The factory-set combination is 0-0-0-0.
  2. Push the reset lever left and down. The lever will remain in this position while you reset the combination.
  3. Rotate the dials to your desired combination.
  4. Push the reset lever back into its original position - back and to the right.
  5. Close the compartment door and scramble the dials to lock. This Key Safe has a new combination. Don't forget to store your new combination in a safe place.

For further guidance on how to set or reset the combination on your lock, please watch our instructional video or see the instruction sheet.

5400D Instruction Sheet
5401D Instruction Sheet

How do I set the combination on my Master Lock 5422D / 5423D Push Button Lock Box?

To set or reset the combination on your Master Lock 5422D / 5423D Push Button Lock Box:

  1. Open the lock box by entering the combination. If you're setting the combination for the first time, press the "CLEAR" (C) button and then press the "OPEN" button.
  2. Locate the 12 yellow plastic slotted buttons behind the door.
  3. Use the included yellow recode tool or a small flathead screwdriver, PUSH and TURN the numbers or symbols you want to use to the SET ON position. Make sure that the numbers or symbols that you are not using are set to the SET OFF position.
  4. This lockbox now has a new combination. Be sure to store it somewhere safe.

For further guidance on how to set or reset the combination on your lock, please watch our instructional video or see the instruction sheet.

5422D Instruction Sheet

How do I set the combination on my Master Lock 5424D / 5425D Spare Key Storage Safe?

To set or reset the combination on your Master Lock 5424D / 5425D Spare Key Storage Safe:

  1. Open the compartment door by entering the combination. The factory-set combination is 0-0-0-0.
  2. Use a pointed object, such as a pen, to slide the combination set lever in the direction of the arrow.
  3. Rotate dials to your desired combination.
  4. Close the compartment door and scramble the dials. This key safe now has a new combination. Don't forget to store your new combination in a safe place.

Further guidance is available for the 5424D. Please see our instructional video or instruction sheet.

Further guidance is available for the 5425D. Please see our instructional video or instruction sheet.

5425D Spare Key Storage Safe Instructional Video

How do I set the combination on my Master Lock 5406D Spare Key Storage Safe?

To set or reset the combination on your Master Lock 5406D Spare Key Storage Safe:

  1. Open the compartment door by entering the combination. The factory-set combination is 0-0-0.
  2. Push the reset lever to the left and pull it forward. The lever will remain in this position while you reset the combination.
  3. Rotate the dials to your desired combination.
  4. Push the reset lever back to its original position.
  5. Close the compartment door and scramble the dials to lock. This Key Safe has a new combination. Don't forget to store your new combination in a safe place.

For further guidance on how to set or reset the combination on your lock, please watch our instructional video.

How do I set the combination on my Master Lock 5404DHC Key Safe?

To set or reset the combination on your Master Lock 5404DHC Key Safe:

  1. Open the compartment door by entering the combination. The factory-set combination is 0-0-0-0.
  2. Push the reset lever up and to the right. The lever will remain in this position while you reset the combination.
  3. Rotate dials to your desired combination.
  4. Push the reset lever back into its original position - down and to the left.
  5. Close the compartment door and scramble the dials to lock. This Key Safe has a new combination. Don't forget to store your new combination in a safe place.

For further guidance on how to set or reset the combination on your lock, please see the instruction sheet.

How do I set or reset the combination on my 175 / 176 / 177 / 178 Master Lock Set-Your-Own Combination Lock?

To set or reset the combination on your 175, 176, 177, or 178 Master Lock padlock:

  1. Open the lock using the previous combination. If it is a new lock, you can use the factory-set combination to open the lock. You can find the factory-set combination with the product packaging. Note that the shackle must be open to reset the combination.
  2. Insert the reset tool in the hole on the side of the lock. The reset tool is included in the lock's packaging.
  3. Push the reset tool in and turn 90° in either direction. The reset tool will stay in position.
  4. Set wheels to your new combination.
  5. Turn and remove the reset tool. The lock is now set to a new combination.
  6. Record your combination in a safe place.

For further guidance on how to set or reset the combination on your lock, please watch our instructional video.

How do I set the combination on my Master Lock 643D lock?

To set or reset the combination on your Master Lock 643D lock:

  1. Open your lock by entering the lock combination. The factory-set combination is 0-0-0-0.
  2. Turn the shackle 90° so that the notch on the shackle is aligned with the notch on the lock body.
  3. Press and hold the shackle down. While holding the shackle, set the dials to your new combination. Be sure that the middle of the numbers are lined up with the red stripe.
  4. Lift and return the shackle to the closed position.
  5. Scramble the dials. The lock now has a new combination. Be sure to record your combination in a safe place.
How do I set the combination on my Master Lock 643DWD lock?

To set or reset the combination on your Master Lock 643DWD lock:

  1. Open the lock by entering the combination. The factory-set combination is P-L-A-Y.
  2. Turn the shackle 90° so that the notch on the shackle is aligned with the notch on the lock body.
  3. Press and hold the shackle down. While holding the shackle, set the dials to your new combination. Be sure that the middle of the numbers are lined up with the red stripe.
  4. Lift and return the shackle to the closed position.
  5. Scramble the dials. The lock now has a new combination. Be sure to record your combination in a safe place.

For further guidance on how to set or reset the combination on your lock, please watch our instructional video or see the instruction sheet.

How do I set the combination on my Master Lock 653D lock?

To set or reset the combination on your Master Lock 653D lock:

  1. Open your lock by entering the lock combination. The factory-set combination is 0-0-0-0.
  2. Turn the shackle 90° counterclockwise.
  3. Press the shackle down while turning the shackle another 90° counterclockwise.
  4. Set the dials to your new combination.
  5. Turn shackle back 90° clockwise. Lift, and continue turning clockwise.
  6. Close the lock. The lock now has a new combination. Be sure to record your combination in a safe place.
How do I set or reset the combination on my Master Lock 1550 backpack lock?

To set or reset the combination on your Master Lock 1550 backpack lock:

  1. Align the dials to the previous combination. The factory-set combination is 0-0-0.
  2. Push in the button at the bottom of the lock. While holding in the button, turn the dials to your new combination.
  3. Once the dials are set to your new combination, release the button. The lock now has a new combination.
  4. Record your combination in a safe place.

For further guidance on how to set or reset the combination on your lock, please see the instruction sheet.

How do I set or reset the combination on my Master Lock 1520D / 1523D / 1524D / 1534D lock?

To set or reset the combination on your Master Lock 1520D, 1523D, 1524D, or 1534D lock:

  1. Open the lock and remove the shackle.
  2. Pull off the metal end cap.
  3. Remove all combination wheels.
  4. Make sure the red marks remain aligned with the Master Lock logo. Install the wheels so your new combination aligns with the Master Lock logo.
  5. Snap the metal end cap back into place. If the end cap isn't mounting properly, check the wheels to make sure they are right side up.
  6. Close the shackle and scramble the wheels to lock.
  7. Record your combination in a safe place.

For further guidance on how to set or reset the combination on your lock, please watch our instructional video.

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