Container Markings: Required vs Convention

Storage only? Nothing is federally required.

If your container sits on your property or jobsite and never gets tendered for transport, no federal rule requires an ID number, CSC plate, or weight marking — the container regulations (49 CFR 450-453 and the international conventions) apply only to boxes in international transport. Marking a storage box is a business decision: unit numbers for tracking, your phone number for the free advertising, safety marks for the crew. Local zoning may limit where and how long the box can sit — and a handful of cities (San Francisco, Sacramento, several eastern towns) require the owner's name and phone on containers placed in the public right-of-way, in one case in 4-inch letters legible from 50 feet.

Moving it by truck? The rules mark the truck, not the box.

For domestic highway moves, federal marking obligations attach to the power unit (the USDOT name/number rules we verify state-by-state) and to the chassis, which the intermodal equipment provider must mark. The container itself carries no federal domestic marking requirement — with the big exception of hazmat placards on four sides when placarded loads ride inside.

International service? Now the full stack applies.

• ISO 6346 identification — the customs conventions require the familiar number block: a BIC-registered owner code ending in U, 6-digit serial, check digit, and size/type code, in characters at least 100 mm (about 4 inches) tall in a contrasting color. That's why our ID sets offer a 4-inch ISO-conforming size.
• Weight markings — tare weight is required by the customs conventions; the standard MAX GROSS / TARE / NET panel in KG and LBS is universal practice.
• CSC safety approval plate — required, and here's the honest part most decal sellers skip: the CSC plate must be a permanent, fireproof plate that survives 1,000°F for 15 minutes (49 CFR 451.23). A vinyl decal legally cannot be a CSC plate, so we don't sell one. If a vendor offers you a "CSC plate sticker," walk away.
• Re-examination date marking — containers must be periodically examined (every 30 months max) and marked with the next exam date. Unlike the plate, the regulation explicitly allows this marking "by decal, sticker, stencil, or other means" (49 CFR 452.1) — a decal is the standard way to do it.

The conventions everyone assumes are law

"NOT FOR HUMAN OCCUPANCY" stickers, unit numbers, company phone panels, 9'6" high-cube height warnings — all industry convention, not legal mandates for storage boxes. Good conventions, worth following (the height warning has saved plenty of canopies), but no inspector will cite you for their absence on a storage container. We label them honestly on every product page.

Can I put my own code on my own box?

Yes. On a private storage container you can mark any ID scheme you like — it only has to be a BIC-registered code if the box enters international service. Don't imitate another company's registered prefix, and if your fleet might ever ship internationally, registering your own owner code with the BIC is straightforward.