I don't actually believe it's necessary to get a machine serviced every year, unless maybe if you sew a *lot* of hours with it every single day of the year. As long as you clean the lint out of it regularly it should be able to go much longer than a year without servicing. If it's an older machine that needs oiling, keeping it oiled regularly is a necessity but again, it shouldn't need professional servicing annually unless it is really used a *lot* -- like in a commercial business setting, perhaps, or if you sew 8 hours a day at home seven days a week year-round.