Many small businesses and the self-employed may be forgiven for thinking that competition law only applies to large, often multi-national companies. However, they would be wrong to do so. A number of very recent cases in which SMEs and self-employed professionals have either been found to have been involved in anti-competitive practices, or are under investigation for suspected anti-competitive behaviour, provide a very strong warning that all businesses, however small, must be aware of and comply with the Competition Act 1998. In a new note, specialist competition law barrister Matthew O’Regan considers these cases and their implications for the owners and directors of SMEs and self-employed traders and professionals.