HOLEQUEST have a long-standing and prestigious list of clients, who trust and rely on HOLEQUEST to provide the service they require.
| Aberdeen Harbour Board | University of Aberdeen | British Geological Society | D Harrison & Son |
| Aberdeen City Council | AMA Consultants (Edinburgh) Ltd | Alistair Burrell Associates | Howie Forest products |
| Aberdeenshire Council | AMS Associates | AMCO Rail Ltd | Impetus Waste Management |
| Argyll & Bute Council | Asher Associates | Ascot Environmental Ltd | Kinegar Sand & Gravel |
| City of Edinburgh Council | Addison Conservation & Design | M & J Ballantyne Ltd | John Laidlaw & Son |
| Clackmannanshire Council | Barron Wright Partnership | Bi-Water Leslie | Laing Traditional Masonry |
| East Lothian Council | BEAR Scotland | Blinkbonny Quarry (Borders) Ltd | T McLeod & Sons |
| Fife Council | Elliott & Company | Border Concrete Products Ltd | McNicholas Construction Services |
| Glasgow City Council | Grontmij Group | Border Construction Ltd | Merlin Entertainment (Dungeon) Ltd |
| Midlothian Council | Halcrow Group | Caledonian Maritime Assets | Milklink |
| The Moray Council | Harley Haddow | Calmac Ferries Ltd | Peter Moran Ltd |
| Northumberland County Council | Arch Henderson LLP | Cameron Harris D & B | The Morrison Partnership |
| Perth & Kinross Council | Jacobs | Clermont Developments | Murray & Burrell |
| North Ayrshire Council | McKay & Partners | CKD Galbraith | OGL Groundwater |
| Renfrewshire Council | Mott Macdonald | D & A Leisure | Quattro Consult Ltd |
| Scottish Borders Council | David Narro Associates | DITT Construction Ltd | REC Ltd |
| Shetland Islands Council | Quattro Consult Ltd | Danwood Concepts Plus Ltd | R J T Excavation |
| West Lothian Council | Seed & Co | John Duguid Partnership | ROK Civil Engineering |
| Scottish Executive | Scott Wilson Rail | Dunadd Ltd | John Rae Ltd |
| Scottish Enterprise | Stewart Engineering | DuPont Teijin Films | A & GE Redhead |
| Historic Scotland | SLR Consulting | ECO-living | K Renton Architects |
| Balcaskie Estate | Wardell Armstrong LLp | Earth Energy Ltd | Reywood Construction |
| Buccleuch Estates | WYG Environment | Emtelle UK Ltd | SBS Cumbria |
| Lothian Estate | Ashleigh Scotland Ltd | Encompas Ltd | Scottish & Southern Energy |
| Marchmont Estate | Dumfries & Galloway Housing Partnership | Entrepose Industrial Services | Scottish Water |
| Roxburghe Estate | Loreburn Housing Association | Envirocentre | Speyroc Ltd |
| Wemyss & March Estates | Scottish Borders Housing Association | Fjordhus Ltd | Stonemasonry Services |
| NHS Dumfries & Galloway | Lagan Homes | Four Acres Charitiable Trust | Talisman Energy |
| NHS Lothian | Tweed Homes | Glendevon Energy Ltd | West Coast Sea Product |
| University of Dundee | Aden Homes | Graham Construction Ltd | Wind Energy (Earlshaugh) Ltd |
| University of Edinburgh | Tarmac Northern | H2Ology Ltd | Wind Prospects |
