Individuals who "construct or alter" buildings and structures in California must be licensed by California's Contractors State License Board (CSLB). Prior to becoming a fully licensed contractor, applicants must have four years of work experience so that they can take the CSLB's contractor exam. Once licensed as a contractor, the applicant can add further specifications. One such specification is a C-33 license. This classification allows the person to work as a contractor on sites that require painting and decorating.

Be at least 18 years old and have at least four years experience in a construction business.

Contact the California CSLB and order an Application for Original Contractor's License and the Certification of Work Experience forms. You can contact the CSLB by calling 800-321-2752. Fill out the application and the work experience form and return them to the CSLB. The mailing address for the CSLB is P.O. Box 26000, Sacramento, CA 95826.

Pay the filing fee for the materials. As of 2010, the fee is $250 for the original contractor's license.

Wait for the CSLB to process your materials and to send you a notice to "appear for examination." Follow the instructions; take and pass the CSLB examination. Upon passing, you will receive your Original Contractor's License.

Add the C-33 classification to your original license. Once you are licensed, you can add as many qualifications as you want (so long as you are qualified for them). Contact the CSLB and ask them to send you an "Application for Additional Classification." Fill out the application and return it. The cost is $50 to add a classification as of 2010.

Take and pass the C-33 exam. Just as you received a notice of examination for your original license, the CSLB will do the same for adding the C-33 qualification. Follow the directions on the notice and pass the exam to obtain your C-33 classification.