The United States Postal Service (USPS) requires residential mailboxes to conform to a number of rules and regulations. The standardization of mailboxes helps to ensure the safety of mail carriers and the items they deliver. While some rules apply to all mailboxes in general, there are separate, specific regulations for locking, package or wall mount mailboxes.
General USPS Requirements for Curbside Residential Mailboxes
- All manufactured mailboxes must meet the internal and external dimension requirements of the USPS.
- Curbside mailboxes must be placed on the right-hand side of the road and facing outward so that mail carriers can access it easily without leaving their vehicle.
- The box or house number on a mailbox must be represented in numbers that are at least 1 inch tall, and they must be positioned on the front or flag side of the box.
- Mailboxes must be placed 6 to 8 inches away from the curb; the slot or door must be 41 to 45 inches from the ground.
- Curbside mailbox posts should be buried less than 24 inches deep and made from wood no larger than 4 inches high by 4 inches wide. Steel or aluminum pipes with a 2-inch diameter are also acceptable.
- Newspaper receptacles may be mounted on the same post as the mailbox, but they must not contact it directly or be supported by it.
USPS Regulations for Locking Mailboxes
Locking mailboxes effectively prevent theft of incoming mail. They must meet the same functional requirements as standard mailboxes and must be approved by the postmaster.
- Slots for incoming mail must be at least 1.75 inches high by 10 inches wide.
- Protective flaps on locking mailboxes must be oriented inward so that mail carriers can place mail into the slot without additional effort.
- Locking mailbox slots must be large enough to hold the resident’s normal daily volume of mail.
- Slots must also be large enough to accommodate unfolded US Priority Envelopes.
- Locks cannot be used on contemporary or traditional mailbox designs.
- USPS carriers do not open locked mailboxes and do not accept mailbox keys.
USPS Regulations for Package Mailboxes
A T3 mailbox is sometimes called a large rural or Package Mailboxes. It shares most regulations with standard mailboxes but can accommodate larger items.
- Dimensions for an approved package mailbox are no larger than 22 1/2 inches long, 8 inches wide and 11 1/2 inches high.
USPS Regulations for Wall Mount Mailboxes
Wall Mount Mailboxes are convenient in areas where postal carriers travel on foot. They are also helpful for residents who are physically impaired.
- The USPS does not have specific dimension requirements for wall mount mailboxes, but local codes and regulations may apply.
- Customers should seek advice from their local postmaster or mail carrier before installing a wall mount mailbox to ensure proper placement and uninterrupted mail delivery.
- The flap on a wall mount mailbox should operate smoothly and reliably.
- Mail carriers must have safe and unobstructed access to the mailbox.