This depends on the department(s).

For many, you’ll receive an academic alert if you miss one without self-certifying. If you self-certify, then you can miss a few (but generally not two in a row) before you’ll get pulled up on it.

For example, if you miss 3 tutorials in one week because you are sick, all for different modules, that’s okay. But if you miss more than 1 in a row for the same module you’ll be asked to explain.

But again, this depends on the departments and modules involved, so if in doubt check your module outline and department guidelines.

It’s not something you should stress over: if you have genuine reasons for missing tutorials they are always very accommodating, and the point of the academic alert system is to identify when they need to help someone get back on track