Round: 26 Ground: Carpet indoor
| ITF Germany F14 | 2015/09/30 10:10 | Sieber, Marc v Nejedly, Pavel | 6-3,6-4 |
| ITF Germany F13 | 2015/08/29 11:00 | Sieber, Marc v Daniel Masur | 3-6,2-6 |
| ITF Germany F13 | 2015/08/28 15:00 | Granollers, Gerard v Sieber, Marc | 4-6,3-6 |
| ITF Germany F13 | 2015/08/27 12:30 | Wagner, Hannes v Sieber, Marc | 6-4,1-6,1-6 |
| ITF Germany F13 | 2015/08/25 11:25 | Jonas Trinker v Sieber, Marc | 3-6,3-6 |
| ITF Turkey F18 | 2015/05/07 07:00 | Sieber, Marc v Peter Heller | 5-7,3-6 |
| ITF Turkey F18 | 2015/05/06 10:20 | Wakita, Shunsuke v Sieber, Marc | 2-6,2-6 |
| Turkey F12, Singles Qualifying | 2015/03/26 09:30 | Sieber, Marc v Rodriguez-Pace, Ricardo | 4-6,3-6 |
| ITF Germany F14 | 2015/09/30 08:00 | Kossler, Bernd v Podzus, Janis | 3-6,7-5,7-6 |
| ITF Austria F8 | 2015/08/16 07:30 | Kossler, Bernd v Zibrat, Janos | 4-6,3-6 |
| ITF Austria F8 | 2015/08/15 07:30 | Kossler, Bernd v Forster, Robin | 6-3,6-0 |
| ITF Austria F6 | 2015/07/28 12:40 | Dolezel, Filip v Kossler, Bernd | 7-6,6-1 |
| ITF Austria F6 | 2015/07/26 15:15 | Koncilia, Lukas v Kossler, Bernd | 4-6,2-6 |
| ITF Austria F6 | 2015/07/25 11:30 | Kossler, Bernd v Yvo Panak | 7-5,3-6,6-4 |
| ITF Austria F5 | 2015/07/23 15:50 | Kossler, Bernd v Spec, Matic | 7-6,6-3 |
| ITF Austria F5 | 2015/07/22 09:25 | Dmitriev, Kirill v Kossler, Bernd | 6-1,5-7,2-6 |