Posted on

Is A Mailbox Required For My Business, and What Are the Requirements?

Search all the help articles:

← All Topics

Whether your business will be required to have a mailbox of some sort that’s approved by the USPS will depend on one factor. Ask yourself: will your business be open during all postal delivery hours?

If yes, then you do not necessarily need a USPS-approved mail receptacle. If your business is open during postal delivery hours, it’s possible for a postal employee to simply drop your mail off to a staff member working at a front desk. This approach could work well for smaller businesses.

Of course, this approach may not work well for larger businesses. Perhaps your employees do not have the time to sort mail or you need additional security. In that case, you’ll need to follow certain requirements with whichever type of mailboxes you install:

Door Slots. According to the USPS, door slots must:

  • The slot must be at least 7 inches long and an inch and a half wide/tall
  • The slot can be installed either vertically or horizontally
  • The slot must be 30 inches or higher from the floor

Wall-mounted mailboxes. To follow USPS requirements, wall-mounted mailboxes must be:

  • Pre-approved by the USPS or approved by the postmaster if designing your own mailbox (look for the USPS-approved badge when purchasing)
  • Must be installed on the side of your building
  • Must allow safe and easy access
  • Check local codes. There are no dimensional requirements for these mailboxes from the USPS, but these could still apply

Curbside Mailboxes. These mailboxes, which can be single or come with multiple boxes, follow the same requirements as residential curbside mailboxes, which are:

  • Curbside mailboxes must be 6-8 inches back from the curb
  • They must be no higher than 45 inches tall, and the door must be between 41 and 45 inches off the street surface
  • The address must be on the same side as the flag or on the front of the mailbox
  • The post (which must be no bigger than 4 x 4) must be buried between 12-24 inches in the ground
  • Newspaper receptacles can’t touch or support the main mailbox compartment(s).

Cluster, Vertical and Horizontal Mailboxes. 4C units are pre-approved by the USPS. You will need to:

  • Contact the post office so they can install a master lock and locks for parcel lockers
  • Ensure no customer compartment is more than 67 inches from the floor and at least one compartment is no higher than 48 inches off the floor
  • Ensure no compartment is closer to the floor than 28 inches
  • Make sure the master lock is between 3 and 4 feet from the floor
  • If you’re replacing old 4B horizontal or vertical units, you must purchase the same type of mailboxes and install them into an unmodified opening or onto an unmodified wall. Otherwise, you’ll need new 4C units.