Losing the key to your mailbox can be one of the worst things, especially if it happens on a day when you’re expecting really important mail. However, there’s no need to despair because these days it’s fairly easy to solve this problem by getting a replacement key or simply changing the lock.

Here are a few different approaches that you can use to retrieve your lost mailbox key, based on your situation and where you live:

Keys for Tenants

If you’re a tenant that’s renting a flat or a home that has an integrated mailbox system, then your first step should be to report the matter of your lost mailbox key to your landlord or superintendent. Different properties differ in their policies when it comes to what approach you should take in reporting a lost mailbox key, but the safest one would be to make the report in writing and then follow it up with an in-person visit.

The best way to get a timely response once you’ve made your request for a replacement is to make the request as soon as you discover the lost key to mailbox because it might take a couple of days before your request is processed and you have a new key. Keep in mind that the sooner you report the lost key for mailbox, the sooner you’ll be able to access your mail. Also, you may have to pay a fee of $4.40 for a replacement key if the mailbox is owned by the U.S. Postal Service.

Keys for Post Office Mailbox

The best part about opening a mailbox at your local post office is that they always give you two keys, so that you have a spare to turn to when you lose the first one. However, should you lose both keys, you’ll have to fill in what is known as ‘Form 1094’, which is basically a request for a new replacement key, and pay the key fee as well as the refundable key deposit. If you notice that your keys are getting really old and worn out, you should return them to the post office so that you can get new replacements for free.

Private Family Residence Keys

Find the contact details of the key manufacturer and give them a call to report that you’ve lost key to mailbox. They’ll ask for your mailbox item number, so be sure to write it down or memorize it so that you have it on hand when it is requested. Furthermore, the manufacturer will request your proof of purchase so that they can confirm that you really are the owner of the mailbox. You will be charged a fee of $7 or more. Processing your report of lost key for mailbox will probably take several days at the most, but in the end, your new replacement key will come in the mail and all your worries will be forgotten.


If you’re in too much of a hurry to wait for these other options, then the fastest way to get your mailbox key replacement done swiftly would be to call on the services of a locksmith. This option will cost twice if not three times as much as the other solutions, as a typical locksmith service call fee starts at $15 or more, subject to your neighborhood and property setup. However, it’s worth it if you’re really pressed for time. That said, calling out a 24 hour locksmith also requires payment for hardware expenses and labor costs required for mailbox key replacement. At this rate, you might find it cheaper to just purchase a new mailbox altogether. So do some research to find out which is the better option for you financially when you’ve lost key to mailbox.

Mailbox Key Replacement in a Condo or Apartment Complex

If you live in an apartment or condo complex that doesn’t have a maintenance contract or a resident maintenance person, then a whole new set of rules apply. You have to take full responsibility for replacing a damaged or lost key for the mailbox. You might even choose to replace the mailbox lock if a previous tenant did not return the key, which we’re going to teach you how to do in a bit. Read on for step-by-step tips on how to replace your mailbox lock, DIY style.

Step One

If you had a key, you’d use it to open the mailbox so that you can get to the back of the lock. However, if you’re reading this article, then we’ll just assume that you’ve lost or damaged your key, in which case you’ll have to hold your fire until the mail delivery guy comes to unlock all of the mailboxes. This will be your chance to get access to the rear end of the lock, which is what you need in order to replace your mailbox lock.

Step Two

Once the rear of the lock has been opened, you’ll see that there’s a clip which is holding the lock together. Take it out using an adjustable wrench, and make sure to turn it until it’s standing straight while touching the rear of the mailbox door.

If you look closely, you’ll notice that the clip itself has an extended lip that should be pulled away with pliers until the clip has been completely detached from the lock. At this point, it’ll be easy for you to remove the lock by pulling or pushing it out through the front of the keyhole.

Step Three

Using a screwdriver, remove the locking cam which is situated on the rear of the lock. If you’re wondering what the cam looks like, look out for a dense ‘S’ shaped metal that acts as the lock’s bolting mechanism when you turn the key.

Step Four

Attach the cam onto the back of your new lock, making sure that the cam’s ‘S’ curve is facing the upper part of the lock to make it easier for the key to turn left or right.

Step Five

Now it’s time to attach your new lock to the mailbox keyhole. Start by looping the nut on top of the lock frame and then use your adjustable wrench to squeeze it firmly in place.

Step Six

Grease the entire locking apparatus with a spray and test the lock by turning the key inside it to make sure that it’s working properly.