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Cluster Box Units vs STD-4C Mailboxes: What's the Difference?

Monday July 15, 2019

Cluster Box Units (CBUs) and STD-4C mailboxes are two popular alternatives to traditional curbside mailbox applications where multiple mailbox units are needed. A form of centralized mail delivery, they allow couriers to drop off and pick up mail at a single unit rather than accessing each tenant's curbside mailbox. While CBUs and STD-4C mailboxes are similar in this regard, however, they aren't necessarily the same. If you're thinking about purchasing either of these centralized mail delivery systems for your neighborhood or residential community, you should familiarize yourself with the differences between CBUs and STD-4C mailboxes.

What Are CBUs?

Also known as a collection box unit, a CBU is a large free-standing unit consisting of multiple individually locked compartments. Some CBUs contain eight compartments, whereas others contain up to 16 compartments. Regardless of size, each compartment is used to deliver and pick up mail for a nearby household.

As explained by the United States Postal Service (USPS), there are both privately owned and USPS owned CBUs. For privately owned CBUs, households must pick up the key for their mail compartment from the property manager or landlord. For USPS owned CBUs, the local post office is responsible for providing households with the key for their mail compartment.

What Are STD-4C Mailboxes?

Like CBUs, STD-4C mailboxes contain multiple individually locked compartments, each of which is used to deliver and pick up mail for a nearby household. The main difference between CBUs and STD-4C mailboxes is that the former is free-standing whereas the latter is mounted. In other words, only STD-4C mailboxes can be mounted in a wall or cabinet. It's a subtle difference that often confuses property developers. Just remember that CBUs are always free-standing, whereas STD-4C mailboxes are always mounted.

The STD-4C standard is designed to replace the USPS's previous STD-4B and 4B+ standards. As of Oct. 6, 2006, all multi-unit residential projects, such as apartments, in the United States must use STD-4C mailboxes.

Which One Should I Choose?

You can use either CBUs or STD-4C mailboxes when developing a neighborhood or residential community. If you're developing an apartment, though, you should stick with STD-4C mailboxes to comply with the USPS's guidelines. Assuming building plans for the apartment were submitted on or after Oct. 6, 2006, you must use STD-4C mailboxes.


About Forsite:

Welcome to Forsite! You’ve found your best source custom curbside mailboxes and cluster mailboxes. We manufacture and install upscale site amenities throughout the United States. 

Forsite can provide you with everything for your Master Planned Community or  Residential Development. You can create a uniform, upscale appearance and increase property values by "bundling" Forsite’s integrated package of fashionable and durable mailboxes, post and wall mounted lighting, street (way) signs monument and entry signage as well as the desired amenities such as Bollards, Benches, Litter Receptacles and Bike Racks. 

You can count on the experts at Forsite to help improve the quality of your community today. Contact us today to get started by talking to one of our experienced team members at 855-537-0200.