| | PR Agency Name | Location |  |  |  |  |
 | Magna Communications Ltd | .23d West Street, Wimborne, Dorset
| | | | |
 | Magnetic Team Ltd | .Upperbrook Farm, Atlow,Ashbourne,Derbyshire [Derbyshire] [East Midlands] [England] | | | | |
 | Magnificent | .71 Chepstow Road, London. [Greater London] [South East] [England] | | | | |
 | Magnificent PR | .A-Z Studios
3-5 Hardwidge St
London [Greater London] [South East] [England] | |  | |  |
 | Magnificent PR | .A-Z Studios
3-5 Hardwidge St
London SE1 3SY [Greater London] [South East] [England] | 1 |  | | |
 | Magnum Communications | .29 Pall Mall, London.
| | | | |
 | Magnum PR | .Flat 41, Halcyon Whf, 5 Wapping High St, London.
| | | | |
 | Magpie Ayrshire | .7 Milton Drive, Kilmarnock, Ayrshire [North Ayrshire] [Strathclyde] [Scotland] | | | | |
 | Magpie PR | .80 Main Rd, Leadenham, Lincoln. [Lincolnshire] [East Midlands] [England] | | | | |
 | Mahseer Ltd | .Queens House, 1 Leicester Place, St James, London
| | | | |
 | Mainspring Marketing & Public Relations | . [Kent] [South East] [England] | | | |  |
 | Mainstream Financial Media & PR | .Westmoreland House, 32 Circular Road, Douglas [Middle] [Isle of Man] | |  | | |
 | Maitland Consultancy | .Orion House, 5 Upper St Martins Lane, Soho, London
| |  | | |
 | Man Bites Dog Public Relations | .Unit N2, The Old Market
Upper Market Street,
Brighton & Hove,
East Sussex, [Brighton and Hove] [South East] [England] | |  |  | |
 | Mandarin | .Studio D
11 Bell Yard Mews
Bermondsey St
London [Greater London] [South East] [England] | |  | |  |
 | Mandarin | .55-63 Goswell Road, Finsbury, London
| | | | |
 | Mandate Communications | .5th Floor
36 Broadway
London
| |  |  |  |
 | Mandi's Basement | .42 Redchurch Street
LONDON [Greater London] [South East] [England] | |  | | |
 | Mandy Carter | .Wildwood, Hayes Road, Compton Dundon, Somerton [Somerset] [South West] [England] | | | | |
 | Mango PR | .Caroline House
55-57 High Holborn
London
| |  |  |  |