The National Electrical Code or NEC is a set of standards designed to minimize the risk of electrocution when using electricity. This standard governs the configuration, installation and modification of electrical systems in homes and businesses. The NEC is updated regularly, but not on a yearly basis. Depending on which state you live in, the electrical code may be a year or more behind current NEC standards. Additionally, local governments have their own sets of amendments which also affect how the NEC is implemented.
Compliance to the electrical code is not optional, and any project which does not conform to local electrical codes is subject to interruption or cancellation by local authorities. Before you start a new project involving electrical systems or alterations to an existing system, check your state and local compliance codes to make sure you are authorized to start the project or what licensing may be required before doing so.