An Inside Look at how USPS Cluster Mailboxes Work

September 23, 2019

Florence 8 Door CBU Mailbox SandstoneCurious how cluster mailboxes work? Let’s explore how these community mailboxes function. The USPS authorized the use of multi-tenant mailboxes at the turn of the 21st century.

These types of mailboxes, also known as Cluster Box Unit (CBU) mailboxes, allow postal carriers to deliver mail quickly to several people at once. It also ensures that each tenant’s privacy and security are never compromised. Still curious how all of this is possible? Let’s explore how these ingenious CBU mailboxes function.

CBU Mailboxes for Postal Carriers

With one turn of the key in a CBU mailbox’s high-security cam lock, the front panel of the entire unit opens. This provides the postal carrier access to all the tenant mailboxes. The postal carrier then places the mail into each tenant’s mail slot. If a tenant receives a package that is too large for their personal mailbox, the carrier places the package into a parcel locker. A designated key for that locker is also placed in the tenant’s mailbox. Then, the postal carrier closes the front panel door and securely locks the CBU mailbox.

CBU Mailboxes for Tenants

When a tenant needs to retrieve their mail, they simply use their private mailbox key to open and close their mailbox door. If the tenant notices a parcel locker key in their mailbox, they may use it to open the corresponding locker and retrieve their package. Once the parcel locker has been opened, the key remains “trapped” in the lock and can only be removed by the postal carrier on their next visit. For more information about the benefits of parcel lockers, check out our blog Adding Parcel Lockers Improves Tenant Retention.

CBU Mailboxes: The Breakdown

8 Door 4 CBU Traditional BlackThe Basics 

CBU mailboxes come in configurations of eight, twelve, thirteen, or sixteen compartments. Each unit comes standard with an outgoing mail slot and a master door. One parcel locker is included in the configuration for units with ten or more compartments. Additional parcel lockers may be ordered. Visit the Florence Manufacturing page to view more details about CBU mailbox parts.

Finish Options

CBU mailboxes are available in black, postal grey, dark bronze, and sandstone. All finishes are durable powder coats.

Mailbox Keys

Each lock comes standard with three keys. This allows the property manager to retain a master copy while giving each tenant two keys.

Mailbox Numbering

CBU mailbox doors can be identified with either standard silver adhesive placards or engraved numbers. Both the adhesive placards and engravings are customizable. The MailboxWorks strongly suggests that mailbox door numbers do not correspond to tenant office or apartment numbers to ensure privacy.

Mailbox Security

Our CBU mailboxes offer advanced safety features. The heavy-duty pedestal mount is bolted securely to the ground. A thick aluminum wrapping and reinforced corners add to the anti-pry technology. An anti-fishing comb and a sloped hood on the outgoing mail slot provide protection from mail theft. For more details about the high-security features on CBU mailboxes, check out this information!


Upgrading to CBU Mailboxes?

The MailboxWorks cluster box units have been officially licensed by USPS as the “design standard” that all other commercial mailbox manufacturers must follow. Learn more about why cluster box units are the Most Popular Solution for Centralized Delivery Projects and the Favored Solution for Multi-Tenant Delivery.

The experts at The MailboxWorks provide professional guidance and can help you with the ordering process. Ask about our discounted Florence cluster mailboxes when you order in multiples! For more information about CBU mailboxes at The Mailboxworks, please send us an email or call us toll-free at 1-866-717-4943.

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