• 4C Horizontal Mailboxes


    High Security 4C Mailbox Emerges as Commercial Mailbox Stalwart

    The 4C mailbox first introduced to the commercial mailbox industry in 2006 is quickly becoming the general public’s commercial mailbox of choice. The end users seem to prefer the STD-4C horizontal mailbox due to its design, security, and versatility which in comparison to other commercial mail receptacles, the 4C mailbox clearly prevails. Originally designed and USPS sanctioned for wall installations the 4C horizontal mailbox has experienced an evolution of product options and styles as commercial mailbox suppliers seek to differentiate themselves from another. The high security 4C mailbox mimics the cluster box design and security, however offers far more flexibility in terms of customization of module configurations. Many industry insiders feel this why the STD-4C mailbox has quickly become the fast growing category of commercial mailboxes.

    4C Horizontal Mailbox Styles

    4C horizontal mailboxes were originally designed for new construction applications where the mailboxes were to be recessed into a wall or contractor created a mail kiosk. Commercial mailbox manufacturers seeing the popularity of the USPS-STD-4C mail receptacle aggressively pursued alternative styles of 4C horizontal mailboxes. The pursuit of alternative styles of 4C mailboxes resulted in a surface mount collar being developed allowing for recessed cabinets to be wall mounted, mail kiosks being created to provide a manufacturer provided structure for the STD-4C mailboxes, and a full line of pedestal 4C mailboxes to provide an additional choice for pedestal mailbox buyers. The 4C mailbox product extensions have been smashing success with the 4C pedestal mailboxes leading the way. If the manufacturers of commercial mailboxes can succeed in convincing the Postal Service to certify the 4C pedestal mailbox many industry insiders believe the 4C mailboxes will eventually surpass the most utilized commercial mailbox which is currently the cluster box unit.

    4C Horizontal Mailbox Sizes

    USA Building Supplies offers an assortment of 4C horizontal mailbox modules for clients to choose from. 4C mailbox modules throughout the commercial mailbox industry are available in;

    • single column width
    • double column width


    The width of the single and double wide USPS-STD-4C module will only vary slightly from manufacturer to manufacturer. The depth of the 4C mailbox will typically be about 17”. The other variable that does vary from commercial mailbox manufacturers is the height of the module. USA Building Supplies arranges thet recessed 4C horizontal mailbox modules they represent according to height because typically most designers and architects prefer to make module selections within the same height grouping. This selection practice also assists the installation contractor of the mailboxes. Generally speaking, most construction projects with a significant amount of residents will use the taller 4C mailbox modules to minimize the amount of wall space needed. Mid-sized and smaller 4C modules often are used in smaller construction projects. Senior housing projects are the one exception to the rule as far as relating the project size to the height of the mailbox module. This reason for this exception is the concern for resident in the upper mailbox compartments having to reach to get their mail. Contact a USA Building Supplies’ 4C horizontal mailbox specialist to receive layout assistance!

    STD-4C Horizontal Mailbox Versatility

    The major reason for the commercial mailbox user and buyer’s preference for the STD-4C horizontal mailbox is the flexibility the receptacle brings to the table. The 4C mailbox allows for different resident, parcel locker, and outgoing mail door sizes therefore allowing for customization of the mail receptacle to meet the buyer’s requirements. It is recommended when customizing your 4C mailbox configuration to speak with an experienced commercial mailbox representative so he can provide you design assistance. Typically, most industry suppliers provide this service free of charge.

    4C Horizontal Mailboxes have developed over the Past Decade

    In 2006 when specification USPS-STD-4C was finalized and subsequently enacted the manufacturers of 4C horizontal mailboxes rolled out their product offerings shortly thereafter which had less options and flexibility. As true with many product introductions the customers drove the additional innovations of the 4C mailboxes. Potential clients wanted a wider selection of powder coat finishes to choose from and most manufacturers responded with additional color choices. The marketplace wanted additional preconfigured 4C modules to choose from and the suppliers listened. As time passed customers continued to drive the evolution of the 4C horizontal mailbox by demanding;

    • additional tenant doors sizes
    • larger outgoing mail collection compartments
    • varying sizes of parcel lockers.


    STD-4C mailbox manufacturers stepped up and began to add this flexibility to their product lines. Recessed mounted 4C mailboxes were the first and only installation method when these receptacles were first brought to market. The public demanded more USPS-STD-4C mailbox mounting options and the factories responded with surface, pedestal, and kiosk installation alternatives.

    USPS-STD-4C Mailboxes Mounting Options

    USA Building Supplies offers a wide selection of mounting options for USPS-STD-4C mailboxes. Recessed mount 4C horizontal mailboxes are the installation option most often used by end users. The reason why this mounting option most prevalent is a recessed mount mailbox gives a new construction project a flush finished appearance. Typically, construction project managers will already have the framework of the mailbox selection set forth in their division 10 specifications and architectural plans. Another mounting option for 4C mailboxes is surface mounting. This is accomplished by a fully assembled collar that supports and houses the USPS-STD-4C mailbox. This type of installation comes in handy for existing buildings that prefer to not cut a hole into the wall. However, it should be noted that 4C mailbox module will project out from the wall approximately 18” and should be planned for accordingly. Another alternative for installing your 4C horizontal mailbox is a freestanding enclosure. The 4C horizontal mailbox enclosure allows the end user great flexibility on where they install their centralized mail receptacle. If the 4C mailbox is for postal delivery, please consult with postal officials to gain mutual agreement before purchasing. Recently, manufacturers have introduced the 4C pedestal mailbox which has been in high demand. The 4C pedestal mailbox is not yet received USPS Certification; however local postmasters have been willing to grant local variances in certain circumstances. USA Building Supplies’ representatives are ready to help facilitate your next 4C horizontal mailbox purchase.

    Postal Access versus Private Use 4C Horizontal Mailboxes

    USA Building Supplies offers 4C horizontal mailboxes that can be for postal access or for private access. The difference between postal and private access 4C mailboxes is relatively simple. Postal access 4C mailboxes are for U.S. Mail delivery and private access 4C horizontal mailboxes are for private applications. Postal access 4C receptacles come prepared of the Post Office installed arrow lock. Private access 4C modules come equipped from the factory with commercial lock. Private use 4C mailboxes have been used for laptop lockers, medical record storage, and in private corporate mail rooms. Postal approved 4C mailboxes are used all over the United States including

    • multi-family buildings
    • offices
    • subdivisions
    • other types of developments

    Make sure your 4C Mailboxes are USPS-STD-4C Compliant

    USA Building Supplies specializes configuring 4C horizontal mailbox configurations that meet your wishes and are also USPS-STD-4C sanctioned. The Postal Service in 2006 after years of deliberation with commercial mailbox industry experts released the new USPS-STD-4C regulation for wall installation mailboxes. The new postal regulation for 4C mailboxes enhanced the security of the mail receptacle, increased the minimum door compartment size, and required a parcel locker to resident ratio of one parcel locker for every ten residents. USPS-STD-4C regulation also set forth new mailbox installation requirements. 4C mailbox installers need to be aware that there must be 28” from the finish floor to the bottom resident compartment. In addition, the top row of the mailbox locks cannot surpass 67” from the finished floor. An exception to this installation standard is if your installation contains no resident compartments in the bottom row, then you have the option to install 15” from the floor. Front loading and rear loading 4C horizontal mailboxes are available however a secure room is required for a rear load installation locations. USA Building Supplies will walk you through the process of making sure your mailboxes are 4C compliant. Get in touch with USA Building Supplies USPS-STD-4C regulation consultant today!

    4C Mailbox Finishes

    USA Building Supplies offers 4C mailboxes in aluminum, gold, bronze, or sandstone powder coat finish at the same cost to the client. Color samples are available from the factory to compare the different finishes. 4C mailboxes from USA Building Supplies can be used both in interior and exterior environments because of the durable finish. The finish on the receptacles is scratch resistant so the unit can keep its appearance for years. Touch up paint is available from the factory if needed. Contact a USA Building Supplies professional today for selection assistance on your 4C mailbox finishes.

    4C Horizontal Mailbox Solutions

    USA Building Supplies is dedicated to being your supply partner for our customers when they purchase 4C horizontal mailboxes.  Most experienced buyers realize that often minor annoyances happen when procuring goods from a supplier. Solution conscious vendors provide quick solutions to these issues when they occur. USA Building Supplies will not only provide a fix to your issue, but we hope to educate you in advance here, by providing you the information needed regarding these nuisances. Typical common issues that happen once in a while when a buyer orders a 4C mailbox are a mailbox door sticking after the unit has been installed, lost keys or a need for extra keys, and parcel locker keys snapping off in the captive lock. High security 4C horizontal mailboxes have minimal pry points as set forth by USPS regulations. Occasionally, during shipment the module will shift slightly, causing a mailbox door or two to stick. Usually this issue is not discovered until after the 4C receptacle is installed. The solution to this problem is rather simple. Open the mailbox door that is sticking and tap on the door using a rubber mallet in the opposite direction the door is catching on. Clients also are often confronted with the issue of lost keys or needing duplicate keys for their residents. If all of the keys are lost for the tenant lock a new lock must be ordered for replacement of the existing lock. Key blanks can be ordered by providing the key code etched on each key in the case of when duplicate keys are needed. What happens if a captive keys snaps off in the lock of the parcel lockers? Unfortunately, in this scenario a new captive lock must be purchased. Contact USA Building Supplies’ problem solving representative today!

    4C Horizontal Mailboxes Operate Efficiently

    USA Building Supplies offers single and double wide 4c horizontal mailbox modules that function capably for the both the mail carrier and the tenants. The single wide 4C mailbox module has an outgoing mail collection door that doubles as the post office master entry door. Upon approaching your 4C horizontal mailbox to deliver the mail, the postal carrier will access the master door with the master key for the USPS provided arrow lock. Once the mail carrier gains access to the control door of your 4C mailbox, the letter carrier will push up on an internal lever in this compartment which will release the face panel for access to all the compartments at one time. The single wide 4C mailbox module face panel will hinge on the right side of unit and then once the mail carrier has delivered the mail he will lock the face panel back in its original position. The individual resident doors are keyed differently and the tenants can only gain access to their dedicated compartment. The 4C horizontal mailbox that is referred to as a double wide module operates similar to the single wide module. The double wide 4C mailbox module’s master access door is located in the middle of the right panel when looking at the front of the unit. Once the mail carrier gains access to your 4C mailbox, he will first open the right panel and then will gain entry to the left panel. Thus, the 4C double module will open like French doors for the USPS. The residents gain access to their mail in the same fashion as the single wide modules.

    Shop our entire selection of commercial mailboxes now for high quality and affordable mailbox solutions.