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USPS Commercial Mailbox STD-4C Regulations & Requirements

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Standard 4C Mailbox Specifications

All new designs approved for new construction and major renovation require U.S. Postal Service STD-4C compliant mailbox systems. USPS commercial mailbox specifications include:

  • Minimum size requirement of 12” w x 15” d x 3” h
  • Minimum number of parcel lockers based on a 1:5 parcel locker to customer compartment ratio
  • Improved security requirements for entire receptacle
  • Standardizes and improves tenant compartment lock design
  • Adds testing requirements to verify indoor/outdoor use
  • Meets Americans with Disabilities Act (ADA) standards
Commercial Mailbox System
Commercial

Commercial

USPS delivery & private delivery

Shop indoor and outdoor mailboxes for apartment complexes, condos, offices, colleges, or local businesses. Choose high end vintage style large cluster mailboxes or simple small indoor lockable horizontal mailboxes for a lobby area or entryway.
Indoor

Indoor

Invest in quality

Our inventory features horizontal and vertical indoor metal mailboxes for commercial buildings and businesses. Equip a small apartment complex or an entire university with secure storage for mail, internal documents or packages – USPS approved or private use options available.
Mailroom

Mailroom

Totes, shelves, sorters, and more

We supply professional mailroom supplies and equipment for commercial and municipal buildings. Choose from our wide selection of mailroom totes, sorters, shelves, carts, and more.
4C Horizontal

4C Horizontal

USPS 4C horizontal & 4C depot style boxes

We supply Florence 4C horizontal and 4C depot style mailboxes for commercial and municipal buildings for a highly secure option. Horizontal 4C mailboxes are USPS approved (STD-4C) and 4C depot style mailboxes are for private deliveries only.
USPS Approved

USPS Approved

Commercial, Apartment, & Residential Units

The U.S. Postal Service will only deliver to your mailbox if it's up to their standards – including box size, location, slot dimensions and identification info. Our USPS approved mail boxes include easy installation instructions to ensure you meet all official guidelines.
Residential

Residential

Quality one-time purchase

Cheap home mailboxes are flimsy and put your belongings at risk. For single-house rentals or individual home owners, a metal mailbox poses the best security and defense. Choose a wall mounted mail house or traditional locking box with post.
Outdoor

Outdoor

Apartments, schools, or businesses

Outdoor metal mailboxes with secure locking options protect possessions from theft and harsh weather. Choose decorative or standard cluster box units or locking residential mailboxes (USPS approved or for private use only).
Drop Boxes

Drop Boxes

Parcel & package receptacles

Florence drop boxes for parcels, packages, and mail are always sturdy and secure. Your packages and letters will be kept safe until your mailman arrives to collect the contents.

ADA Compliance for 4C Standard Mailboxes

US Mail Supply carries Florence Versatile 4C mailbox suites which are designed to meet or exceed the USPS specifications outlined above and in the *Federal Register/Vol. 69, No. 171/September 3, 2004/Rules and Regulations POSTAL SERVICE, 39 CFR Part 111, Standards Governing the Design of Wall-Mounted Centralized Mail Receptacles.

ADA Compliance – the USPS 4C Standard includes a requirement to meet Americans with Disabilities Act** (ADA) standards. (See pg. 53,809*) The ADA section that covers clear space and reach dimensions is noted below:

ADA Standards for Accessible Design, ACCESSIBILITY GUIDELINES FOR BUILDINGS AND FACILITIES Appendix A to Part 36 – Standard for Accessible Design Section 4.2 Space Allowance and Reach Ranges

IMPORTANT NOTE TO ALL ARCHITECTS, SPECIFIERS, DESIGN LAYOUT PROFESSIONALS AND INSTALLERS – All 4C Units shall be designed such that they are in compliance with the following installation requirements:

  1. At least one customer compartment shall be positioned less than 48 inches from the finished floor
  2. No parcel locker compartment (interior bottom shelf) shall be positioned less than 15 inches from the finished floor
  3. No tenant 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


Shop USPS approved mailboxes available for sale from U.S. Mail Supply.