What is a Cluster Box Unit?
A cluster box unit (CBU) is a free-standing, pedestal mailbox with 8, 12, 13, or 16 individually locked mailbox compartments and up to 2 integrated parcel lockers. Since all cluster boxes are USPS Approved, they are the most common community mailboxes on the market. (To view other commercial mailboxes, click here). They also come in six (6) different architectural colors and can be modified to fit any community design. The colors include Sandstone (our most popular), Black, Bronze, Gray, Green, and White.
Our manufacturers equip every CBU with an outgoing mail slot and houses between one and two parcel lockers for package delivery (note: you can purchase an eight-tenant unit with up to four parcel lockers).
Installation: If you need someone to install your cluster mailbox, we offer installation options on each CBU product page. Choose the option that best suits your requirements. After you place the order, we will send you info regarding the installation process and the next steps. For more details on our CBU installation program, please see this article. Once you install your CBU, you can contact your local postmaster to come out and install their proprietary Arrow Lock, which allows the mail carrier to deliver to all tenants.
Note: While the Cluster Mailboxes found on this page are pre-approved by the USPS for centralized mail delivery, customers may wonder if the same is true of 4C pedestal mailboxes. The answer is: no, 4C pedestal mailboxes require pre-approval by the USPS before you purchase and install if you intend to use them for USPS mail delivery. If you intend to use a 4C pedestal for private use, then this should not be a point of concern. If you have questions about this, feel free to give us a call.
Choosing the right Cluster Mailbox (CBU)
Are you looking for the right cluster box to fit your needs? We can help! We offer a wide selection at the lowest prices to meet your next commercial or residential development project's needs. If this is your first time purchasing a cluster box unit, below is some information you may find helpful. Of course, feel free to call us at (866) 707-0008 or open a chat window (bottom left of the site) with one of our reps if you need immediate assistance.
Options for USPS approved Cluster Mailboxes include:
The Standard CBU is USPS Approved
The following CBUs are already pre-approved by the USPS:
- The 8-Door
- The 12-Door
- The 13-Door
- And the 16-Door (our best-seller and the best option for the value)
We also offer a 4-Door unit with larger doors (model # 1570-4T5) and an 8-Door unit with 4 parcel lockers (model # 1570-8T6) that are also USPS approved. If you are unsure which of these options best suits your needs, feel free to call and speak to one of our product experts. They can help you find the right unit within your budget.
The USPS Approved Cluster Mailbox is available here in six different tenant door configurations and in six architectural color options among which to choose. We offer quantity pricing for two or more units.
We always include pedestals.. Shop with confidence, and feel free to call, email, or open a chat with one of our product experts.
You can also see a similar selection in High Security and Decorative options below.
The High-Security CBU (also USPS Approved)
While our manufacturers build the standard cluster box to prevent theft, the High-Security pedestal option can significantly reduce the risk of mail and identity theft. You can purchase the vandal-proof fasteners to attach to the unit's anchor bolts for these units. The manufacturer has also designed the master front loading door to prevent prying, making it nearly impossible for mail thieves to break open the master door. In general, the latest industry-standard Cluster Mailboxes boast a thicker, reinforced metal gate with a larger diameter hinge rod on all tenant doors.
The Decorative CBU (also USPS Approved)
Decorative CBUs are identical to the standard units, except for the Pedestal and Cap. For Auth-Florence models, you can choose either the Classic Decorative unit or the Traditional Decorative unit. For Salsbury models, you can select the Regency option. Images of these three options are displayed below.

4C Pedestal Mailboxes
Note: All manufacturers of 4C Pedestal Mailboxes have discontinued these units. They will no longer manufacture these mailboxes in the U.S. as of 11/30/2020.
The 4C Pedestal mailbox is very similar to the CBU, except the 4C pedestal is not pre-approved by the USPS. These units will require USPS approval if used for USPS mail delivery and outgoing USPS pick-up. We strongly recommend that you contact your local postmaster for approval of the 4C Pedestal Mailbox before completing your purchase. Feel free to call and speak with one of our product experts if you need more information.
CBU Accessories and Related Products
We offer a wide selection of cluster box accessories and related products. Among the best-sellers, we offer the standard USPS Approved Parcel Locker. You can select from either a 2-Parcel unit or a 4-Parcel unit, and in one of six color options to match your selected unit. Although standard numbering will ship the fastest, custom numbering is available.