Call or visit the Planning Division of the City's Community Development Department for basic zoning information and requirements. If your business will be located in a non-residential location, you will need to verify that your proposed business is of the type allowed in that specific location. If you propose a business which is considered a more intense land use than the previous business at that location, you may need to provide additional parking. If you want to alter either the interior or the exterior of the building, you will need to submit construction plans for all such changes in order to obtain a Building Permit. Extensive exterior modifications require Planning Commission approval before applying for a Building Permit. You will also need to consider exterior signage for your business as part of the building and/or site modifications you propose. For some types of businesses, you may also need to contact San Mateo County or the State of California for additional permits/licenses. Your last step will be to apply for a City Business License. Ideally, you would obtain all governmental approvals before signing a lease. If your business will be located at your place of residence in Millbrae, you will need to apply for a Home Occupation Permit as well as a City Business License.