Ideally, an air conditioning system should be serviced once a year, with regular inspection after every 3 to 4 months.
Also, never try to service your air conditioner yourself because the interior of the AC consists of a lot of components which may get damaged if not handled carefully. Always hire a professional HVAC service company so that its licensed technicians will service your AC efficiently without damaging any component.
However, remember that the servicing period varies from model to model. Additionally, how often you use the AC unit determines if your AC needs to be serviced once a year or once after every few months.