| M MacKey - Farming of cattle, dairy farming |
| M R Commercials - Maintenance and repair of motor vehicles |
| Mac Transport (NI) Ltd - Activities of other transport agencies |
| Magowan Tyres - Sale of motor vehicle parts and accessories |
| Masterwood - Manufacture of builders' carpentry and joinery |
| Mauds Ice Cream Parlour - Restaurant |
| Mauds Ice Creams - Manufacture of ice cream |
| McBride Tool Services - Wholesale of machine tools |
| McCambridge Associates - Advertising |
| McCann - Other supporting land transport activities |
| McCollam (Heating & Plumbing) Ltd - Plumber |
| McConnell Funeral Services - Funeral and related activities |
| McConnell Of Doagh - Bar |
| McKay (Newtownards) Ltd - Dispensing chemists |
| Millar Carriers - Other supporting land transport activities |
| Mirror Robes Direct - Manufacture of other kitchen furniture |
| Modern Tyre Service - Sale of motor vehicle parts and accessories |
| Module Road & Race - Manufacture of motorcycles |
| Moore's Garage - Maintenance and repair of motor vehicles |
| Motor Care - Sale of motor vehicle parts and accessories |
| Motorfreight - Freight transport by road |
| MW Tyres & Exhausts Centre - Sale of motor vehicle parts and accessories |
| Mccann - Car Park Operators-Flat |
| Mckay(newtownards)ltd. - Retailers Of Drugs |
| M & M Engineering Construction - Manufacturers Of Fabricated Metal Products |
| Mcconnell Funeral Services - Funeral Directors |
| Micael Scott - Farming |
| Mcburney & Mckinstry - Animal Feed Retailers |
| Mauds Ice Creams - Ice Cream Manufacturers And Suppliers |
| Maurice Lynn Motors - Used Car Dealer |
| M D M Plumbing & Heating - Plumbing And Hydronic Heating Contractors |
| Mauds Ice Cream Parlour - Ice Cream Stands Or Dairy Bars |
| Mccandless Opticians - Optician |
| Mainway Transport - Hlge Contrs |
| Mckee & Sons - Wood Tv Radio Etc Cabinet Mfrs |
| Mrt Gardenscapes - Wood Partition & Store Fixture Mfrs |
| MB Tyres & Auto Centre - Tire Shop |