Paint contracting without a license is against the law in most US states. The construction bidding process usually requires a contractor to prove he holds a state contractor's license by providing his license number when presenting his bid. The process for obtaining a valid painting contractor's license will vary from state to state. Most state licensing agencies require an application to be completed and an exam to be taken before awarding the license. Keeping a license active may require proof of continuing education.
Contact your state's licensing and regulations board and request a licensing package from your state's licensing office. Each state defines and manages its own licensing process and will have its own requirements and process for obtaining a trade license. For example, the state of New Mexico awards its painting contractor license through the New Mexico State Regulation and Licensing Department under the heading of Construction Industries Division.
Read through all the material provided by the state's licensing office. Identify the application, the test or exam information and any educational or work experience requirements that you will need to address before and after the exam is taken--continuing education is often a licensing requirement. For example, in the state of New Mexico, painting contractors are licensed under the umbrella of a general contractor's license with a special classification that requires them to have at least two years' experience before applying for a license.
Assemble the materials you need to provide to the state. Obtain proof of your previous work experience and any other documentation, references and insurance that may be required. For example, the state of New Mexico requires proof of financial responsibility in the form of a $10,000 Consumer Protection Code Bond and proof of a New Mexico Tax ID number.
Study for and take the licensing exam. Some states may outsource the management of the exam to a third party, which will require the contractor to schedule his own exam and pay for it separately from the application. A state may also require a completed application before the exam is taken. Review your state's application process to determine the manner and order the process is designed to occur.
Fill out the application and return it to the state along with any fees requested. Make sure the application is filled out accurately and completely--incomplete applications could delay a license. Pay close attention to the fees required for a complete application. For example, New Mexico requires two separate checks to accompany an application--one for the application and one for the actual license.
Some painting needs fall outside the scope of a general contractor's license and might be considered work a handyman would include in his services. Check your state's descriptions of a painting contractor and a handyman to determine what type of license, if any, you may need.