| Name | Character | Episodes |
|---|---|---|
| Jordan Long | DS Murray Boulting | 36 |
| Sanjeev Bhaskar | DS Sunil 'Sunny' Khan | 36 |
| Nicola Walker | DCI Cassie Stuart | 24 |
| Peter Egan | Martin | 24 |
| Lewis Reeves | DC Jake Collier | 24 |
| Sinéad Keenan | DCI Jessica 'Jessie' James | 12 |
| Alastair Mackenzie | John Bentley | 12 |
| Kate Robbins | Kate | 11 |
| Andrew Lancel | Steve James | 10 |
| MyAnna Buring | Melinda Ricci | 6 |
| Hayley Mills | Lady Emma Hume | 6 |
| Liz White | Fiona Grayson | 6 |
| Ian McElhinney | Lord Tony Hume | 6 |
| James Fleet | Chris Lowe | 6 |
| Rhys Yates | Jay Royce | 6 |
| Victoria Hamilton | Juliet Cooper | 6 |
| Kevin McNally | James Hollis | 6 |
| Hannah Gordon | Grace Greaves | 6 |
| Clare Calbraith | Anna Sidhu | 6 |
| Tom Courtenay | Eric Slater | 6 |
| Brian Bovell | Ray Wilton | 6 |
| Susan Lynch | Liz Baildon | 6 |
| Jan Francis | 6 | |
| Ruth Sheen | Lizzie Wilton | 6 |
| Bryony Hannah | CATH | 6 |
| Phaldut Sharma | Ram Sidhu | 6 |
| Lucy Speed | Marnie Barton | 6 |
| Lorraine Ashbourne | DI Tessa Nixon | 6 |
| Emma Fielding | Amy Hollis | 6 |
| Mark Frost | Dave Adams | 6 |
| Mark Bonnar | Colin Osborne | 6 |
| Andy Nyman | Dean Barton | 6 |
| Tom Austen | Josh Cross | 6 |
| Gemma Jones | Claire Slater | 6 |
| Bernard Hill | Father Robert Greaves | 6 |
| Badria Timimi | Sara Mahmoud | 6 |
| Sara Stewart | Mel Hollis | 6 |
| Trevor Eve | Sir Phillip Cross | 6 |
| Indra Ové | Maria Carr | 6 |
| Tom Rhys Harries | Elliot Hollis | 6 |
| Martina Laird | Ebele Falade | 6 |
| Brid Brennan | Suzanna Reid | 6 |
| Siobhan Redmond | Derran Finch | 6 |
| Gerald Kyd | Adrian Mullery | 6 |
| Dominic Power | Les Slater | 6 |
| Rosie Cavaliero | Marion Kelsey | 6 |
| Hebe Beardsall | Cheryl | 5 |
| Michelle Bonnard | Sal | 5 |
| Tamzin Malleson | Caroline Greaves | 4 |
| Lucinda Dryzek | Claire Finch | 4 |
| Grainne Keenan | Debbie | 3 |
| Abhin Galeya | Mehdi Hussein | 3 |
| Nabil Elouahabi | Rashid Ghulam | 3 |
| Magnus Bruun | Josef Morten | 3 |
| Mark Oosterveen | Graham Saville | 3 |
| Maria Friedman | Rebecca | 3 |
| Hayley Tamaddon | Judy Mexbury | 2 |
| Simon Bubb | John Caxton | 2 |
| Andrew Neil | Mr. Salthouse | 2 |
| Andrew French | Carl | 2 |
| Joshua J. Parker | Jordan | 2 |
| India Ria Amarteifio | Kaz | 1 |
| Lisa Faulkner | Flick | 1 |
| Rita Davies | Mary White | 1 |
| Alex Jennings | Dr Tim Finch | 1 |
| Neil Morrissey | Pete Carr | 1 |
| David Troughton | Geoff | 1 |
| Yusra Warsama | Alaya Ali | 1 |
| Derek Griffiths | Chris Blackwood | 1 |
| Simon Greenall | Terry | 1 |
| Tessa Peake-Jones | Sheila | 1 |
| Bobby Lockwood | Nathan | 1 |
| Zephryn Taitte | Scott | 1 |
| Charlie MacGechan | PC Ellis | 1 |
| James Quinn | Dennis Grimshaw | 1 |
| Alex Clatworthy | 1 |