Do I need to apply for a passport before applying to universities for the September intake?

It’s not strictly mandatory at the very beginning, but it is highly recommended to have your passport ready early in the process. Many universities ask for a copy of your passport as part of the application documents, so not having one can delay your application.
Also, if you plan to take English proficiency tests like IELTS or TOEFL, a valid passport is required as the primary ID for registration and exam day. Beyond this, you’ll need your passport for visa applications and other formalities later in the process.
So while you can start some initial steps without it, getting your passport made early helps avoid unnecessary delays and keeps your application timeline smooth.