You can apply to study abroad at any time. Some students decide to leave their home country  at the end of their high school at 17/18 years of age. In France, students can also consider studying abroad after pursuing a "prépa". This allows them to have a back-up plan if they do not get the schools they are targeting, or they may, in fact, decide that they prefer this option.
For students applying at the end of their high school, it is important to remember that chances are increased and the process more manageable if you start early. In this way you have the chance to attend open days or taster courses at universities which interest you. It also gives you the chance to prepare for any language exams such as IELTS or TOEFL and to start thinking about country/university/programme choices.
It is important to bear in mind that most anglophone universities will need to receive your application by January. For some institutions it is earlier. In the UK, the deadline for Oxford or Cambridge, Medicine and Veterinary Science, is the 15th October of the year prior to the year that you intend to start. For example, if you wish to study at Cambridge or Oxford, or study Medicine in the UK from September 2027 the latest date you can apply is the 15th October 2026.
It is also a good idea to leave plenty of time for the Personal Statement or essay. This is an important part of the application stage and requires time and patience. A good Personal Statement or Essay/Motivation Letter, for Non UK schools, can increase your chances of success.
Whenever you approach International Horizons with your project, we will do our best to offer you the greatest chance of success and will inform you of the different deadlines for each targeted school/university.