USDOT Number cost
New DOT number is free
There is no initial fee to open a new DOT number. It is free of charge. Once you have a DOT number there are several other costs associated with having a DOT number. Those additional fees will be based on the type of operation as different operations may need to comply with different types of compliance.
One example for such compliance is the UCR registration. It's a fee that all drivers who operate in an Interstate commerce must pay yearly. The more vehicles operate under the DOT number the higher the fee you must pay.
Also, you will have to complete the MCS-150 form. This is a form that must be filed once every 2 years based on the last 2 digits of your DOT Number.