USPS Cluster Mailboxes

A cluster box unit (CBU) mailbox is a freestanding, pedestal-mounted mailbox that consists of multiple mailbox compartments and parcel lockers that can lock individually. The United States Postal Service (USPS) will deliver mail and parcels to the mailbox compartments and parcel lockers.

back to top

The mail carrier has a master key to an Arrow Lock that allows them to access all compartments at once. After delivering the mail, the mail carrier will lock the CBU up and each tenant will retrieve their mail from their individual mailbox compartment and their packages from the parcel lockers with a key.

back to top

Salsbury cluster box units cost as low as $1,835.00.

back to top

Cluster mailboxes are not always owned by the USPS. In general, the cluster mailbox belongs to whoever initially installed the unit. Some units are purchased and installed privately, while others are installed by the USPS.

back to top

Cluster mailboxes can be privately owned or owned by the USPS.

back to top

Salsbury CBU mail compartment sizes are 12” W x 3” H x 15” D, 12” W x 4-3/4” H x 15” D, or 12” W x 6-1/2” H x 15” D depending on which door size you select. They also include 1, 2, or 4 fully integrated parcel locker(s): Regular (12” W x 10” H) and Large (12” W x 13-1/2” H). Outdoor Parcel Lockers include 2 or 4 front loading 12” W x 19-3/4” H x 15” D parcel lockers.

back to top

According to USPS regulations, the property owners, builders, or developers are responsible for cluster mailboxes. The USPS’s Postal Operations Manual states, “Purchase, installation, and maintenance of mail receptacles are the responsibility of the customer.”

back to top

Salsbury’s durable and corrosion-resistant CBU’s are constructed of heavy-duty aluminum and stainless steel hardware with a powder coated finish that will stand up well to harsh weather conditions. One compartment in each Salsbury CBU mailbox is labeled “Outgoing Mail” and includes a weather protection flap.

back to top

It is a lot more efficient for a mail carrier to deliver mail to one centralized location instead of delivering from house to house. Consequently, CBU’s provide the USPS with both time savings and significant fuel-efficiency on their postal vehicles. With CBU’s, the USPS also reduces labor costs as each mail carrier will be able to more efficiently deliver their mail. Cluster mailboxes are more secure than individual curbside mailboxes. Multiple safety features protect against mail theft. Each tenant is assigned a mail compartment that is secured with a heavy-duty cam. An anti-fish plate on the rear of the outgoing mail slot helps block the tampering of mail.

back to top

Centralized mail delivery is a mail delivery system in which the mail carrier delivers mail for multiple residences at one central location.

back to top

Salsbury Industries’ 3300 Series Cluster Box Units and 3300R Series Regency Decorative cluster mailboxes include mailboxes and lockers that fall within ADA height requirements.

back to top

A parcel locker is a lockable compartment designed to hold packages that will not fit in a standard mailbox compartment.

back to top

Parcel lockers are included with cluster box units, either alongside them or integrated. When a mail carrier is unable to fit a package into a standard mailbox compartment, they will place your package in a parcel locker. The carrier will then leave the key to the parcel locker in your mailbox. (If you look up the USPS tracking number for your package online, you will see a message “Delivered to Parcel Locker” when your delivery arrives.) To get your package out of the parcel locker, you simply need to use the key the mail carrier has left in your mailbox to unlock the parcel locker. The key will have a tag that indicates which locker contains your package. Once you have unlocked the parcel locker and retrieved your package, the key capture system will secure the parcel locker key in place so that it can’t be removed. Only a USPS mail carrier will be able to remove the key with a master key. If you’re still unsure of how parcel lockers work, consult this helpful video.

back to top

This short video will take you through each step in the process of installing a cluster mailbox, showing you exactly what you need to do. It also provides a list of the tools you will need. After you’ve installed your cluster mailbox, you should get in touch with your local Postal Authority to get the master arrow lock installed.

back to top

Salsbury CBU mail compartments are available with “A” size doors (12-3/4” W x 3-1/4” H), “B” size doors (12-3/4” W x 5” H), and “C” size doors (12-3/4” W x 6-3/4” H).

back to top

Salsbury CBU’s come in several colors to choose from—black, bronze, gray, green, sandstone, and white. Other customizable options include custom engraved placards and custom engraved doors (regular or black filled). For a Standard CBU or a 3304 series Outdoor Parcel Locker, you can select a Regency CBU decorative top and a Regency CBU decorative pedestal cover.

back to top

The Salsbury CBU Mailbox Configurator will help you determine the optimal number of mailboxes and parcel lockers needed based on your specific requirements. The CBU Mailbox Configurator provides a summary with elevations, rough opening dimensions, sample installation instructions, model numbers, and other important information. Both Standard 3300 Series Cluster Mailboxes and Parcel Lockers and Regency 3300R Series Decorative Cluster Mailboxes and Parcel Lockers can be configured. Click here to use the CBU Configurator.

back to top