A new semi trucker always ask the question "what decals must I display on the outside of my semi-truck?"
The short answer is: It depends.
For starters, each state has its own laws and regulations but to be up to code, one must display the company name with city and state, along with an MC/MX/FF # and DOT # numbers on both sides of the sleeper. A unit or truck number should be displayed on the door or hood. An annual inspection sticker should be placed on the back corner of the sleeper and IFTA stickers on both doors.
Also, it is required to display a fire extinguisher inside and a electronic logs on the the drivers side door.
Note: A company name decal should match the information on the registration, you could face a fine if the names do not match.
Example: If information on the registration states "Andy's Trucking Company" the cabin decal cannot say "Andy's Trucking INC"
Also, the minimum size of a trucking decal should be 2 inches.