Classification Details
| NMFC | Description | Class |
|---|---|---|
| 133950.00 | Mailboxes, with or without posts or other accessories, or Mailbox Kits, see Note, item 133951, in packages, subject to Item 170 and having a density in pounds per cubic foot of: | |
| 133950.01 | Less than 1 | 400 |
| 133950.02 | 1 but less than 2 | 300 |
| 133950.03 | 2 but less than 4 | 250 |
| 133950.04 | 4 but less than 6 | 175 |
| 133950.05 | 6 but less than 8 | 125 |
| 133950.06 | 8 but less than 10 | 100 |
| 133950.07 | 10 but less than 12 | 92.5 |
| 133950.08 | 12 but less than 15 | 85 |
| 133950.09 | 15 but less than 22.5 | 70 |
| 133950.10 | 22.5 but less than 30 | 65 |
| 133950.11 | 30 but less than 35 | 60 |
| 133950.12 | 35 but less than 50 | 55 |
| 133950.13 | 50 or greater | 50 |
Notes
Note 133951: NOTE-Does not apply on postal call, lock, or mail collection boxes, as named in item 160890.
How to Determine Your Class
To find the correct freight class for your shipment:
- Verify eligibility: finished mailboxes with or without posts, or complete mailbox kits that meet Note 133951. Ship in corrugated boxes or packages as required by Item 170.
- Calculate density for class selection: weigh the carton and compute cubic feet. Example: 24×18×18 in at 30 lb equals 30 ÷ 4.5 = 6.7 PCF. Use the Item 133950 density breaks to pick the class within 50–400.
- Package to protect doors, flags, and coatings: bag hardware, cap post ends, add corner/edge guards, and immobilize posts so they don’t punch through. Double-wall cartons with foam or molded inserts work well.
- Palletize when multiple boxes ship together: keep all packages square to the pallet with no overhang, strap and wrap tightly, and mark fragile panels. Print NMFC 133950 and the calculated density on the BOL to avoid reclass.
Note: All classifications are subject to Item 170. Verify with official NMFC publications for the most current requirements.
Business Value
- Lower costs through density optimization: co-pack posts, hardware, and the box body to raise PCF and potentially qualify for a lower freight class.
- Fewer billing surprises: accurate density and the correct NMFC 133950 on the BOL reduce reclass fees, inspections, and delivery delays.
- Reduced damage and claims: reinforced cartons and restrained posts prevent punctures and bent doors, protecting margins and customer satisfaction.
- Predictable quoting for mixed materials: whether steel, aluminum, or plastic bodies, the density-based rule provides a consistent rating framework for retailers, builders, and e‑commerce shippers.