It depends on your application. If you choose to have the transfer switch installed you will need a permit and the electrician will get the necessary permits for the job. If you choose to operate a portable generator with items plugged into it, you do not need a permit.
However, please let your local utility know that you are running a generator. Line crews may pass you by if they see lights on.
Also, crews in the area can plan on working in the vicinity of an operating generator.