| 1 |  Mondello Park, Race 1 (21 April) |
| 2 | Mondello Park, Race 2 (21 April) |
| 3 |  Brands Hatch Indy, Race 1 (5 May) |
| 4 | Brands Hatch Indy, Race 2 (5 May) |
| 5 | Thruxton Circuit, Race 1 (26 May) |
| 6 | Thruxton Circuit, Race 2 (26 May) |
| 7 | Silverstone Circuit International, Race 1 (8 June) |
| 8 | Silverstone Circuit International, Race 2 (8 June) |
| 9 | Rockingham Motor Speedway, Race 1 (22 June) |
| 10 | Rockingham Motor Speedway, Race 2 (22 June) |
| 11 | Croft Circuit, Race 1 (13 July) |
| 12 | Croft Circuit, Race 2 (13 July) |
| 13 | Snetterton Circuit, Race 1 (9 August) |
| 14 | Snetterton Circuit, Race 2 (9 August) |
| 15 | Brands Hatch Indy II, Race 1 (25 August) |
| 16 | Brands Hatch Indy II, Race 2 (25 August) |
| 17 | Donington Park National, Race 1 (7 September) |
| 18 | Donington Park National, Race 2 (7 September) |
| 19 | Oulton Park, Race 1 (21 September) |
| 20 | Oulton Park, Race 2 (21 September) |
It was also the last year that BTCC admitted Production Cars to the grid, as the Production Class has ended after the 2003 season.
Source-https://en.wikipedia.org/wiki/2003_British_Touring_Car_Championship