U.S. Postal Service STD-4C Specification Information
Effective October 5, 2006, all new designs approved for NEW CONSTRUCTION AND MAJOR RENOVATION require U.S. Postal Service STD-4C compliant mailbox systems. The new USPS-4C Standard includes the following specifications:
- A new minimum size requirement for mailboxes (12"W x 15"D x 3"H).
- 4C parcel locker requirement based on a 1:5 parcel locker to customer compartment ratio (effective July 2020).
- Strengthens security requirements for the units.
- Standardizes and improves tenant compartment lock design.
- Adds testing requirements to verify acceptability for either indoor or outdoor use.
- Meets Americans with Disabilities Act (ADA) standards.
Salsbury Industries 4C Horizontal Mailboxes 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 in the Design of Wall-Mounted Centralized Mail Receptacles.