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Versatile Front Loading Mailbox with 14 Tenant Compartments

(View all from Auth-Florence)
SKU: WL-4C16S-14BM  |  View All 4C Front Loading Horizontal Mailboxes 13 to 14 Doors
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$237.00 (20%)

Volume Discount Pricing
2 - 5$899.00
6+ $860.17
Please note: This large commercial mailbox is made to order and cannot be returned. For delivery of U.S. mail, contact your local postmaster for approval.
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Mounting Option*

Door Identification*

According to manufacturer:
Usually ships in 2 to 3 weeks
Ships directly from the factory floor to ensure the quickest available delivery.

Understanding 4C Mailboxes by Overall Height


Actual: 56-1/2"H x 31-9/16"W (Double) or 17-1/2"W (Single) x 17"D / Rough Opening: 55-9/16"H x 30-5/16"W (Double) or 16-1/4"W (Single) x 17"D

(Compartment Types)
(20 MB1, 2 PL15)
(19 MB1, 2 PL15)
(7 MB2, 2 MB3, 2 PL15)
(1 MB2, 6 MB3, 2 PL15)
(9 MB1, 1 PL15)
(3 MB2, 1 MB3, 1 PL15)
(3 MB3, 1 PL15)
# Mailboxes (Total)201997943
# Parcel Lockers (Total)2222111
# Collection1111111
# BINS0000000
# Mailboxes Under 48"8733311
Module Weight (lbs)171163157140978162


Actual: 56-1/2"H x 31-9/16"W (Double) or 17-1/2"W (Single) x 17"D / Rough Opening: 55-9/16"H x 30-5/16"W (Double) or 16-1/4?W (Single) x 17"D

(29 MB1)
(14 MB1)
(4 PL3, 1 PL4, 1 PL5, 1 PL15)
(3 PL4, 1 PL5, 2 PL6)
(1 PL15, 1 PL5, 1 PL6)
(Compartment Types)
291400000# Mailboxes
0000863# Parcel Lockers
1110000# Collection
0002000# BINS
17800000# MB under 48"
17096766511310525Module Weight

Required Height from the Floor

Install at specified heights AFF (Above Finished Floor) to ensure USPS installation requirements are met:

  • If your installation is for USPS delivery and contains any tenant compartments in the bottom row, the minimum height from the floor is 28 inches.
  • If your installation contains no tenant compartments in the bottom row, you have the option to install at a minimum of 15 inches from the floor to be compliant with ADA and USPS requirements.

As we mention in USPS Approved or Private Delivery?, any 4C mailbox on Budget Mailboxes listed as USPS approved already meets these specifications, so your only concern would be to ensure that your installation location is configured properly for the specific 4C you intend to purchase and install.

Numbering Your Tenant Doors

Rather than assigning mailbox ID plates that match apartment or house numbers, sequential or standard numbering may help you meet the accessibility regulations related to your project. Standard numbering may also provide greater security and privacy for residents who do not wish for their home or unit address to be displayed on a specific tenant box. Even so, custom numbering and custom engraving are each available as additional options if standard numbering will not suit your needs.

4C Quick Reference Guide

For more information regarding USPS regulations and our available 4C door height configurations, please see this detailed page.

4C Horizontal Mailboxes

USPS Approved Mailbox

The 4C Horizontal is the industry standard for recessed mounted centralized delivery. Unlike the CBU, the 4C unit is usually recessed in a wall, indoors or outdoors, or in a kiosk (typically outdoors).

However, you can purchase the 4C with a surface mount collar or free-standing kiosk if you do not intend to install the units into a wall. These can be purchased with or without parcel lockers for package delivery, and can be selected for either USPS or private delivery. Available in a variety of door configurations and architectural colors, the 4C mailbox is an ideal solution for apartment complexes and commercial buildings.

In our product description below, you will find information covering a variety of common 4C mailbox questions as well as detailed specs that you can apply to your next new construction or renovation project.

The Industry's Best Product Warranty

5 Year Product Warranty

Florence provides an unrivaled five-year warranty on its products, from the date of shipment when purchased from an Authorized Florence Dealer like Budget Mailboxes. Click here to view full details on the product warranty or call us at (866) 707-0008 if you still have questions.

Design and Other Specifications

Optional Anchor Bolts

Effective October 5, 2006, all new designs approved for New Construction and Major Renovations require U.S. Postal Service STD-4C compliant mailbox systems. The new USPS 4C Standard includes the following specifications:

  • A new compartment form factor minimum size requirement of 12 in. w x 15 in. d x 3 in. h
  • Eliminates the vertical form factor (5 in. w x 6 in. d x 15 in. h) design
  • Introduces a parcel locker requirement based on a 1:10 parcel locker to customer compartment ratio
  • Strengthens security requirements for the entire receptacle
  • Standardizes and improves tenant compartment lock design
  • Adds testing requirements to verify acceptability for either indoor or outdoor use.Introduces quality management systems provisions
  • Enhances design flexibility for concept, ergonomics, and materials
  • Meets Americans with Disabilities Act (ADA) standards

The following design and security features are the industry standard for all 4C Mailboxes:

  • Pre-configured modules with integrated parcel lockers in 14 different height options
  • Thick, reinforced collection door to prevent theft
  • Master front-loading door with interlocking, overlapping seams to prevent prying
  • Integrated outgoing mail collection compartment with weather-protection hood and anti-fishing comb
  • Single-piece extruded door hinge to prevent prying
  • Solid aluminum frame protects adjacent customer/collection compartments

Exclusive to Auth-Florence 4C Mailboxes:

  • Hardy stainless steel latching hook cam on every tenant door with double-latching cam on all oversized doors
  • Double-latching parcel locking mechanism design for added door security and strength
  • Multi-unit connector kit hardware supplied with every module for easier installation across larger openings

4C mailboxes are designed to meet or exceed the USPS specifications. See here for more details.

Fully Integrated parcel locker(s) with key trapping lock
Interlocking, overlapping seams to prevent prying
Standard decals or 3/4" H engraving
Solid aluminum integrated outgoing mail collection compartment prepared for USPS installed Arrow Lock
Integrated Outgoing Mail Slot with weather protection hood
Product and manufacturer ID serial tag
Heavy duty tenant cam lock with three keys
Stainless steel hold open door catch on each side of master gate
Easy release handle to open master gate
Aluminum comb prevents mail fishing in outgoing mail collection compartment
Rugged, weather-resistant powder coat finish
Heavy duty cam latches through frame for added security

How many tenant doors do you need?

What is included with the CBU?

This may be the most common question guiding a customer's search for the right 4C mailbox, as it should be. The options are diverse: you can purchase a single 4C mailbox for 1 tenant or configurations with 20 tenant boxes and 2 parcel lockers.

If you already know the number of tenant doors you need but aren't sure which configuration to choose, here are some questions you can answer to help guide you before purchasing:

  • What size tenant doors do you need? The 4C mailbox offers tenant boxes in three sizes: MB1 (standard), MB2, and MB3. The higher the number after the "MB", the taller the tenant box. So:
    • An MB2 slot is 6 ¾ in. High
    • An MB3 slot is 10 ¼ in. High
  • Do you need parcel lockers included with your mailboxes?
    • Note: the USPS requires one parcel locker for every ten (10) tenant boxes, which is why we sell multiple 4C configurations that already include the required number of parcel lockers.
    • If you purchase 4C mailboxes without parcel lockers, we recommend choosing recessed parcel lockers in the same height class so that the two units will match aesthetically (see more info on Height Classes).

USPS Approved or Private Delivery?


In a nutshell, here are the key differences between a USPS approved and a private delivery 4C horizontal mailbox:

  • A USPS approved mailbox meets USPS regulations for height, width, installation location, ADA accessibility compliance, and compartment size. Luckily for you, we already designate the mailboxes that meet these criteria, so all you really need to know are:
    • The number of tenants that will need access to the mailbox
    • The type of installation: whether the units will be recessed into an existing wall, mounted to an existing wall via surface mounted enclosures, or free standing in a 4C mailbox kiosk
  • (Note: if you find any of this confusing at first, don't worry. We cover these topics in Installation Types and Options below).

  • A mailbox for private delivery doesn't have to meet any of the USPS regulations since it will be serviced by an in-house mail department. This is most common with universities, dorms, or organizations that distribute mail in-house. If you purchase a commercial mailbox for private use, the appropriate lock will be installed and keys will be included with the unit.
  • If you want the gritty details on USPS specifications, we recommend you visit this article as it contains a thorough overview of height regulations, ADA compliance,* and how to choose mailboxes in the same height class (typically for architects or developers).

    *Note: all 4C compliant mailboxes must meet USPS design and installation requirements to be USPS Approved. Accessibility regulations may vary locally and regionally, so we encourage you to always consult local building codes for the accessibility requirements related to your mailbox project. (See Installation and Accessibility References for additional details.)

Front Loading or Rear Loading?

What is included with the CBU?

Front Loading

Front-loading mailboxes include a Master Loading Door prepared for the USPS Arrow Lock, which provides easy access to all compartments by the US mail carrier. Note: the USPS provides and installs their arrow lock, so you will not find arrow locks included with your mailbox.

Front-loading units are usually more common, whereas rear loading units tend to be less common as they require the mail carrier to load and retrieve mail from a secure room located behind the recessed mailbox (more about rear loading below).

Rear Loading

If you haven't already guessed, the rear-loading mailbox is accessed from the back. These mailboxes include hinged and latching rear doors that are accessed by a secure mail room for USPS use. They do not have a front master loading door. Since there is no locking mechanism on the rear doors, a secure mail room behind mailboxes is required to keep mail secure.

If you still aren't sure whether you need a front or rear loading configuration, contact us and we will help you decide on the best option to fit your specific needs.

What is included with the CBU?

Customize Your Tenant Door ID Layout

What is included with the CBU?
  • Step 1 - Select "Custom Layout Required" from the dropdown option labeled Door ID Layout.
  • Step 2 - After you place your order, we will email you the layout form for you to customize.
  • Step 3 - After you've completed and signed the form, email it back to us and we will finalize your order.
  • Important: To ensure a custom layout is processed correctly, we ask that you complete this form after completing your purchase. For your convenience, we will also email you a copy of the form after your order is placed (note: this only applies if you select Custom Layout from the dropdown options).

Customers purchasing a 4C Mailbox with Standard Numbering or Custom Numbering applied top-down from left to right do not need to fill out this form.

Door ID Options

Door ID Options Door ID Options Door ID Options Door ID Options

Decals: All 4C commercial mailboxes come standard with silver adhesive decals 1.5 inches high by 1.75 inches wide. Black lettering can contain up to five characters per decal.

Engraving: Custom engraving utilizes the USPS Standard US Block font with up to 12 characters per line. This ¾ inch high engraving may be created with or without one of two color fill options (white or black).

See this info sheet for more details on door ID options.

Note: 4C mailboxes selected with custom decals or engraving usually ship in three (3) weeks. We cannot rush orders for units purchased with custom numbering.

Installation Types and Mounting Options

What is included with the CBU?


All 4C Horizontal Mailboxes are sold as recessed units, meaning that they will be installed into a wall. The installation requirements are usually set out in the development's architectural planning. We provide detailed technical docs for each 4C Door Height class as well for each individual 4C model within those classes. Check the Related Downloads tab for available specification documents or, if you can't find what you're looking for there, give us a call at (866) 707-0008.

Surface Mount Collar

(only for front loading mailboxes)
If you do not intend to recess your 4C Mailboxes into a wall, you can mount them to the wall directly using a surface mount collar. The collar is installed to the wall, either indoors or outside, and the matching 4C mailbox is recessed into the collar instead of the wall itself. This is sometimes a more practical solution for developments where recessing into a wall is not possible or for limited wall-depth projects.

What is included with the CBU?
What is included with the CBU?

Free-Standing Depot

(only for front loading mailboxes)
In addition to a surface mount collar, customers also have the option to purchase a free-standing mailbox depot. You do not have to mount these depots (or mail kiosks) to a wall, but can place them in a convenient location either inside or outside the building, provided the location meets local USPS requirements for delivery. You would then recess the 4C mailbox into the depot enclosure.

Color Options

Auth Florence 4C Mailboxes are currently available in eight (8) different color options. The colors are listed below along with their corresponding mailbox swatch. To choose your color, select it from the dropdown options before adding the mailbox to your cart.

  • Silver
  • White
  • Sandstone
  • Postal Grey
  • Gold Speck
  • Antique Bronze
  • Dark Bronze
  • Black

Installation Requirements

USPS Approved Mailbox

Florence Manufacturing USPS Approved 4C mailbox products are designed to adhere to STD-4C regulations. To ensure your project complies with USPS regulations for wall-mounted mailboxes, your mailbox center must be installed according to the following U.S. Postal Service guidelines:

Installation requirements specified in the U.S. Postal Service STD-4C regulation are outlined below:
  1. At least one customer compartment shall be positioned less than 48 inches above the finished floor.
  2. No parcel locker compartment (interior bottom shelf) shall be positioned less than 15 inches above the finished floor.
  3. No customer lock shall be located more than 67 inches above the finished floor.
  4. No customer compartment (interior bottom shelf) shall be positioned less than 28 inches above the finished floor.
  5. The USPS Arrow lock shall be located between 36 and 48 inches above the finished floor.

To view more details regarding installation requirements, visit this page in our resource center.

Meeting ADA Installation Requirements

Accessibility regulations may vary by the type of facility and by governing jurisdictions in your region. Therefore, always consult local building officials and codes for accessibility requirements that could affect your mailbox project.

Installation Manual


Looking for a different document? See our full list of printable PDFs.

Note: Installation instructions are provided as general guidelines. We advise all customers to consult a professional installer. Budget Mailboxes assumes no product assembly or installation liability.

4C Mailbox Accessories

Give your 4C mailbox installation the finishing touch by adding complimentary accessories. These options provide additional conveniences your residents and property managers will appreciate. Most 4C mailbox accessories are USPS Approved, as well.

USPS Approved Mailbox

Key Keepers

Use of a Key Keeper allows postal employees to enter a locked mail room to distribute mail in accordance with USPS regulations. Florence offers a dozen options which usually accompanying the rear-load 4C mailboxes, in matching powder coat finish. Key Cabinets are a great way for property managers to organize all the various keys they must maintain and are available in a Sandstone finish.

USPS Approved Mailbox
USPS Approved Mailbox

Collection Centers

Whether for bundled metered mail, book drop-off, multimedia returns, key drop-off, x-ray collection, or anything else that requires drop-off and collection via secure boxes, we should have what you need. Outgoing drop-boxes or mail slots will supply a safe and convenient place for residents to deposit their items for collection. These units are also designed to complement your existing 4C mailboxes.

16 Door CBU

We are a Google Trusted Store

Google Trusted Store
Shop with Confidence

In accordance with the requirements of the Google Trusted Stores program, Google recognizes and certifies Budget Mailboxes for:

  • An excellent shopping experience
  • Reliable on-time shipping
  • Excellent customer service

What does this mean for you?

We will promptly assist customers in the event that they are unsatisfied with their purchase, and we will make every effort to resolve support cases with the customer directly.

So, think of the Google Trusted Stores stamp as more than just a marketing icon. It's the assurance that we will go the extra mile to resolve your support case, according to our company policies.

16 Door CBU
For Your Reference:

OUR SKU is Auth-Florence 4C16S-14

Dimensions & Weight
Ship Weight:
Versatile Front Loading Mailbox with 14 Tenant Compartments
96.00 lbs
Auth Florence Mfg Co.'s Categorization
versatile - 4C mailbox suites and accessories
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Frequently Asked Questions

Versatile Front Loading Mailbox with 14 Tenant Compartments
Shipping Information:

Shipping Estimate:

Usually ships in 2 to 3 weeks

Stock Status:

In Stock

Ships to:

Ship Method:

FedEx/UPS (Learn More)

Shipping Policy:

Return Policy:

Return Instructions:

Need instructions for replacing 4C parts? Access the full 4C Maintenance Sheet here.

Surface Care and Cleaning 5
Open master loading door(s) of a front loading tenant or tenant w/ parcel module 6
Open master loading door(s) of a front loading parcel only module 8
Open Master Loading door of a trash / recycling bin module 10
Removal of module from wall 12
Replacement of front master loading door hold open device for front loading modules only 14
Replacement of top and / or bottom trim 16
Replacement of front master loading door 18
Replacement of left or right front trim 20
Replacement of hinge rod 22
Replacement of front master load door hook 24
Replacement of tenant compartment door 26
Replacement of single high compartment standard tenant lock 28
Replacement of multi-high compartment standard tenant lock 30
Replacement of combination tenant lock 32
Reset combination of combination tenant lock 34
Replacement of trash / recycling bin access door lock 36
Replacement of access door for front loading modules only 38
Replacement of master lock in access door for front loading modules only 40
Replacement of parcel door spring 42
Replacement of parcel door 44
Replacement of parcel master lock 46
Replacement of parcel tenant lock assembly 48
Replacement of access door latch bracket / MLD release handle for front loading modules only 50
Replacement of shelf 52
Replacement of front master loading door slide 54
Replacement of front master loading door outer hinge 56
Replacement of rear master loading door(s) and their hold open device(s) 58
Replacement of number placard and parcel key tags 60
Replacement of trash / recycling bin flap 62
Service parts list and index 64

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Regarding a Product's Shipping Estimate

Understanding Lead Times

The lead times listed on this product page represent the best-case scenario for shipping estimates. While we may show that a product "usually ships" within a given period, this period should not be confused with a delivery estimate. Rather, we expect the product to ship from the manufacturer's warehouse within this time-frame.

What does this mean for you? Once you place an order on our site, we begin processing the order with the manufacturer. The processing lead time we list on the product page is the most current estimate from the manufacturer regarding the product.

Below, we answer the top three FAQs our customers have regarding delivery estimates.


How long will it take to receive my commercial mailbox?

When you order a commercial or cluster mailbox, we process the order with the manufacturer within 1 business day. Once processed, the order usually ships in the time-frame listed on the product page. Since Cluster Mailboxes are large items, they ship via freight carriers. This means that the transit times for these will usually be 5 to 7 business days.

A few things to note about purchasing a cluster mailbox or similar large, commercial-grade product:

  • The freight carrier will call the number you list on the shipping address a day before delivery to schedule a delivery appointment with you.
  • The manufacturer ships using their chosen freight carrier depending on the products ordered and the delivery location.
  • The majority of online retailers who sell commercial mailboxes (CBUs, etc.) ship directly from the manufacturers, just as we do.
  • If you purchase a commercial mailbox from us and decide to cancel because a competitor lists a "faster" lead time on their site, you may be delaying the time it will take to receive your mailboxes. Why? Because you are placing a new order to be sent to the same manufacturer for processing.
  • If you choose professional mailbox installation with your commercial mailbox purchase, please note that same-day installation is not available. Installation will be scheduled after the delivery of your mailbox. In most cases, installation is completed within one week following delivery.

What if I order multiple products from different brands?

If you ordered multiple products, it is possible that they are made by different manufacturers. If this is the case, your products will ship to you separately from each manufacturer.

For example, if you purchase a Mayne Post with a Whitehall Mailbox, your post will ship from Mayne's warehouse in about 3 business days, but your mailbox will ship separately from Whitehall in about 2 to 3 weeks if customized with address numbers.

How can I estimate my shipment's transit time?

Depending on the carrier and your location, transit times will vary. Delivery estimates are best projected using your carrier tracking number. Once your order ships, we'll send you a shipping confirmation email that includes your carrier (FedEx, UPS, YRC, etc.) and tracking number.

Note: If you place an order with us and do not receive an Order Confirmation email, check your spam inbox. If you still do not see an Order Confirmation email in your inbox, contact us right away at (866) 707-0008 . We will provide you with your Order Number and any other details you need.

What is the CBU Price Match Guarantee?

Price Match

It's pretty simple. If you find this model* cluster mailbox on another online retail site for a lower price, including any shipping and taxes, then we will match that competitor's price.

Before we can match a competitor's price, please note:

  • We will need the exact URL of the product page in question. A screenshot of the competitor website will not suffice.
  • Some competitors hide their freight charges until you enter the checkout, so please keep this in mind.
  • If you are ordering multiple units, check our Volume Discount Pricing table (to the right of our sale price) to see if we're the better price for the quantity you need.

* By "model", we mean a CBU that has the same number of tenant doors and the same manufacturer specifications.

Wall Mount Mailboxes Locking Mailboxes Commercial Residential

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