Custom model

A custom model is anything built of LEGO for sale either on spec or by commission. It differs from a MOC in that it is built as part of a business transaction whereas a MOC is built for personal pleasure. Of course, once built and displayed a MOC could be sold at which point it would probably be desrcibed as a custom model to those outside the hobby.

Many, if not all, LEGO Certified Professionals build custom models but this is not required. Some vendors sell multiple copies of a custom model as sets complete with instructions and box art.