To transport freight across state lines, for hire, you will need to obtain your Interstate Authority. The requirements are based on the GVWR of the vehicles. Vehicles under 10,000 lbs. GVWR: MC number $300,000 Liability insurance Vehicles 10,000 – 26,000 lbs. GVWR: US DOT...

The UCR is the Unified Carrier Registration. This is the program that replaced the SSRS (Single State Registration System). If you have a USDOT number and travel to other states, you are required to have a current UCR registration unless you are leased to another motor carrier operating under... 

No. Each business can only have one US DOT number. You use the same number for all your trucks.

As of March 21, 2011, there is no difference between a Common or Contract carrier. Liability insurance is the only required insurance filing for either type of authority.