Different states require different levels for a construction business just starting out. Many states are currently rewriting their requirements with an eye on assuring the general public that anyone who engages in the construction industry has the training and education to be qualified to operate a construction business.
Many states are requiring that all construction workers are licensed to prove their knowledge and ability when working in the construction industry. To obtain a professional license in any discipline can require a knowledge test and skills test where the candidate must pass the test in order to legal practice their craft.
A business will need to have a license issued by its state authority proving it has the staff with professional licenses to accomplish the construction they are hired to do. These licenses may be limited to certain areas such as a mechanical license in plumbing, more general such as a Master Electrical license holder or a General Builder's license that covers all construction crafts.
Once your business has the construction licenses, you will need to apply for a business license with your local government. To do this, you may have to register your business with the federal and state governments and be issued business identification numbers before your application will be accepted and you are issued a business license for your new construction business.