This study will collect information on side effects and how well Esperoct® (turoctocog alfa pegol (N8-GP)) works during long-term treatment (prophylaxis) in males with haemophilia A. Participants in this study will get the same treatment as they would normally get, if they were not participating in the study. All visits at the clinic are done in the same way as participants are used to, when visiting their doctor. During visits at the clinic participants might be asked for some relevant tests if considered useful by the study doctor. During the visits the study doctor might ask if participants had any side effects since the last study visit. Participants will be asked to note down in their own diary the number of bleeds and how these were treated, as well as their regular prophylaxis. Participation in the study will last for about 5-7 years, depending on when participants join the study. Participants are free to leave the study at any time and for any reason. This will not affect their current and future medical care.