| Name | Country | Region | |
| OJT Investigations Group | Australia | New South Wales | Sydney |
| OJT Investigations Group | Australia | Victoria | Melbourne |
| The Paul Elliott Consultancy (CI) Ltd | British Channel Islands | Guernsey | St. Saviour |
| The Due Diligence and Investigation Company Ltd | British Channel Islands | Jersey | St Helier |
| Walker Love | UK | Aberdeenshire | Aberdeen |
| Walker Love | UK | Ayrshire | Kilmarnock |
| Paul Read Investigations Ltd | UK | BERKSHIRE | READING |
| Blayze Ltd | UK | Cambridgeshire | Peterborough |
| T/A Wilf Hurrell Investigations | UK | Cambridgeshire | Burwell |
| Amsel & Co | UK | Cheshire | Altrincham |
| Austin-Allen | UK | East Sussex | Heathfield |
| The Risk Advisory Group plc | UK | Greater London | London |
| Central Investigation Bureau Limited | UK | Hamsphire | Portsmouth |
| P&D Investigations Limited | UK | Hertfordshire | Welwyn Garden City |
| WM Investigation Ltd | UK | Hertfordshire | Hemel Hempstead |
| Walker Love | UK | Invernessshire | Inverness |
| A E D Global | UK | London | London |
| Research Associates (Paul Hawkes) | UK | London | Marylebone |
| Research Associates (Paul Hawkes) | UK | London | Notting Hill Gate |
| Research Associates (Paul Hawkes) | UK | London | North Kensington |
| Pegasus Investigations Ltd | UK | Midlothian | Edinburgh |
| Mr Andrew | UK | Midlothian | Edinburgh |
| Grant & McMurtrie | UK | Midlothian | Edinburgh |
| Walker Love | UK | Midlothian | Edinburgh |
| Mr Beare | UK | Oxfordshire | Oxford |
| Walker Love | UK | Renfrewshire | Paisley |
| Independant Investigation Co | UK | Somerset | Somerton |
| Walker Love | UK | Strathclyde | Glasgow |
| Grant & McMurtrie | UK | Strathclyde | Glasgow |
| Euro-Tec Investigation Service | UK | Surrey | Egham |
| Hogan and Co. International | UK | Surrey | Farnham |
| De Facto International | UK | Surrey | Twickenham |
| Blayze Ltd | UK | Swansea | Swansea |
| Blayze Ltd | UK | West Glamorgan | Swansea |
| M C McNeill and Co | UK | West Lothian | Bathgate |
| Blayze Ltd | UK | Wiltshire | Swindon |
| Sure Step Investigations | United Kingdom | Gwent | Monmouth |