New Castle County follows Delaware state licensing law, and the county or its cities issue the building permit for the job. Below: the state rule, the places inside the county, and live local coverage.
Delaware has no trade or skills-based contractor license for garage door work; anyone doing contracting business must register with the Division of Revenue for a business license (30 Del. C. ch. 25) and pay gross receipts tax, while building codes and permits are handled by the three counties and municipalities.