How to Get a New Mailbox Key (USPS, HOA or Your Own Box)

How you get a new mailbox key depends on who owns the mailbox. If it is your own curbside or wall-mount box, order a key from the manufacturer, call a locksmith or replace the lock yourself. If it is a USPS-owned cluster box, go to your local Post Office. If an HOA, landlord or property manager owns it, contact them. The post office cannot help with private boxes.

Below we cover each case step by step, what the Post Office actually does when you lose a key, who pays, and when it makes more sense to change the lock (or upgrade to a locking mailbox with a better lock) instead of chasing a copy.

Step 1: Figure out who owns your mailbox

Everything else follows from this. USPS rules make the customer responsible for buying, installing and maintaining most mail receptacles, but USPS owns and maintains some cluster box units (CBUs) itself. Who owns the box decides who holds the lock and key service.

Your mailbox	Usual owner	Who gives you a new key	Who pays
Curbside or wall-mount locking mailbox at your house	You	Manufacturer, locksmith, or you (new lock)	You
Cluster box unit (CBU) in a neighborhood, maintained by the Post Office	USPS	Your local Post Office	You, if you lost all keys
Privately owned CBU in an HOA or subdivision	HOA, builder or property owner	HOA or management company	Set by the HOA or owner
Apartment or condo mailboxes (4C horizontal or older 4B)	Building owner	Leasing office or building manager	Set by the owner or your lease
Post Office Box inside a Post Office	USPS	Post Office counter	You (USPS fee)

Not sure who owns your cluster box? Ask your neighbors, your HOA or the Post Office that delivers to it. HOA residents often assume USPS owns the box when the HOA actually bought it, and the answer changes who you call. Our guide to who is responsible for cluster mailboxes goes deeper on this.

If you own the mailbox: three ways to get a new key

A locking mailbox you bought and installed is your property, and so is the lock. The Post Office does not keep keys for it and does not want them: USPS carriers do not open locked boxes or accept keys, which is why approved locking mailboxes have a slot or hopper the carrier can use without one.

1. Order a replacement key from the manufacturer

Look for a key number stamped on your remaining key, on the lock face, or in your paperwork. Some manufacturers can supply a key from that number. Mail Boss, for example, asks owners to register their key number online for easy recovery, and sells model-specific replacement locks that come with three new keys. Have the model name and key number ready when you contact them.

2. Call a locksmith

A locksmith can usually do one of three things on a residential mailbox: cut a key to fit the existing lock, rekey the cylinder so old keys stop working, or swap the cylinder for a new one. Get a quote for each option. If keys may be in the wrong hands (a previous owner, a lost key ring with your address on it), rekeying or replacing is the better choice.

3. Replace the lock yourself

On most residential mailboxes, changing the lock is a short job with a screwdriver once the door is open. You will need to match the barrel diameter, cam and turning direction. Our step-by-step guide to mailbox lock replacement covers how to measure and swap it. If you own an Ecco E6 wall mount or E8 column mailbox, we carry the Ecco E6 / E8 replacement lock with 2 keys.

If every key is gone and the door is shut, the lock may have to be drilled out first. That is legal on your own mailbox, but never force open a mailbox you do not own.

If USPS owns the mailbox: what the Post Office actually does

For cluster box units owned by the Postal Service, the rules are written down in the Postal Operations Manual (POM), section 632.22, and the USPS FAQ on locked mailboxes and mailbox keys. Here is what they say:

• Three keys at the start. USPS is responsible for giving each customer of a postal-owned CBU a compartment lock and three keys. No key deposit is required.
• No spare keys on file. USPS keeps no duplicate keys. If you lose all of your keys, it installs a new lock and issues new keys at your expense.
• No national price. USPS says there is no set fee for this. The charge is based on local costs, so ask your Post Office what it will be.
• New residents are not charged for the first lock. If the Post Office replaced the lock when the previous customer moved out, the new customer does not pay for that first lock and set of keys.
• You may copy your keys. The POM allows customers to duplicate their keys at their own expense. The Post Office will not do it for you.

The "three keys" figure is what USPS issues with a new lock. It is not a cap on how many copies you can have, so if you still have one key, making copies is usually the cheapest fix. If all three are gone, expect a lock change.

How to request a new lock and keys from the Post Office

1. Search your home, car and bags first. Keys are often misplaced rather than lost.
2. Go to the Post Office that delivers to your address, ideally in person. You can find it with the USPS location finder.
3. Bring photo ID and proof that you live at the address. Your Post Office may ask for something specific, so call ahead if you can.
4. Ask what the lock change will cost and when it will be done. Arrangements and timing vary by office.
5. Ask how to get your mail in the meantime. Some offices will hold it for counter pickup.
6. When the new keys arrive, make a copy and store it somewhere safe.

Do not pry your compartment open or try to remove the lock on a USPS-owned box. Breaking into a mailbox is a federal crime, with up to $250,000 in fines and three years in prison (18 U.S.C. 1705), and the master door on a cluster box is opened only by postal employees.

If your HOA, landlord or property manager owns the mailbox

For privately owned cluster boxes, the POM is clear: the builder or property owner is responsible for providing lock and key service. The USPS FAQ says the same for apartment and condo buildings. The owner or manager buys, installs and maintains the mailboxes and their locks, and USPS cannot help you get into them.

1. Contact your HOA board, management company or leasing office and tell them the key is lost or broken.
2. Ask whether they will cut a copy, rekey or replace the lock, and what it costs. Policies and fees are theirs to set, and some leases spell them out.
3. Follow up if nothing happens. Until the lock is fixed you cannot get your mail, so this should be treated as urgent.

For managers and HOA boards: replacement tenant locks for many commercial units come from the mailbox manufacturer. For Salsbury 4C horizontal mailboxes, see our 4C horizontal locks and key blanks, or contact us with the unit's model. USPS rules for apartment mailboxes also say not to stamp key numbers on the outside of the lock barrels, to keep key records, and that masterkeying is not permitted. Do not touch the carrier's master lock: it belongs to USPS.

How much does it cost to replace a mailbox key?

There is no single price, and anyone quoting a national average is guessing. What we can say:

Situation	What sets the cost
Your own mailbox, you still have one key	A copy cut by a hardware store or locksmith, usually the cheapest route
Your own mailbox, all keys lost	Manufacturer replacement key by key number, a locksmith visit, or a new lock you install yourself
USPS-owned cluster box, all keys lost	New lock and keys at your expense. USPS says there is no set fee; it is based on local costs
HOA or apartment mailbox	Whatever the HOA, landlord or lease sets
Post Office Box	USPS key and lock fees listed in the USPS price list, Notice 123

Call your Post Office, manager or a local locksmith for an actual number before you go.

Should you replace the lock instead of the key?

A new key only makes sense if nobody else can open your box. Change or rekey the lock instead when:

• You just moved into a house with a locking mailbox and do not know who has keys.
• Your keys were stolen, or lost on a ring with your address or car.
• The lock is sticking, rusted or damaged.
• You have had mail go missing.

On your own box that is a do-it-yourself job (see our mailbox lock replacement guide). On a USPS-owned cluster box, ask the Post Office; on a private one, ask management.

How to avoid losing your mailbox key again

• Make at least one spare and keep it somewhere other than your key ring.
• Write down the key number and model, or register them with the manufacturer if it offers that.
• Do not label keys with your address.
• If your current box has a weak lock or no lock at all, consider an upgrade. The Mail Boss Mail Manager ships with a 12-disc high-security wafer lock and 3 keys, and our guide to preventing mail theft covers the rest of the picture.

Frequently asked questions

Will the post office give me a new mailbox key?

Only for mailboxes USPS owns, such as postal-owned cluster boxes and PO Boxes. USPS keeps no duplicates, so if all keys are lost it installs a new lock and keys at your expense. For private boxes, contact the owner or manager.

How many keys does USPS give for a cluster mailbox?

For postal-owned cluster box units, USPS provides each customer a compartment lock and three keys, per the Postal Operations Manual section 632.22. You may make extra copies at your own expense.

Can I copy a USPS cluster mailbox key?

Yes. USPS lets customers of postal-owned cluster boxes duplicate their keys at their own expense. USPS keeps no spare keys, so a copy made while you still have one key is the cheapest insurance.

Who do I call for a new apartment mailbox key?

Your leasing office or building manager. USPS says building owners and managers are responsible for apartment mailboxes and their locks, and the Post Office cannot open or rekey them.

How do I get a key for a mailbox at a house I just bought?

Ask the seller first. If no key turns up, order one from the manufacturer by key number, call a locksmith, or replace the lock yourself, which also locks out anyone who kept an old key.

Shop locking mailboxes

Ready to upgrade? Browse our locking mailboxes or, for HOAs and developers, our community cluster mailboxes. Questions about a specific lock or model? Contact us and we will help you sort it out.

******It is always recommended to contact your local postmaster prior to installation. While most of our mailboxes are USPS-approved your local postmaster may have specific preferences in terms of mailbox types and installation location******