If you break the conditions of your Tier 4 visa, you may not be allowed to stay in the UK. The Home Office can revoke your visa and force you to leave the country. They can also ban you from re-entering the UK for a period of time.
Visa conditions are strict and breaking them can have serious consequences. You are responsible for making sure that you are complying with all conditions, so be sure that you understand what they are. You can find a full list of conditions on the Home Office website.
As your visa sponsor, your university is required to report you to the Home Office if they suspect that you are breaking the conditions of your Tier 4 visa. Many of the Tier 4 conditions centre on your academic responsibilities. It is important that you attend all your lectures, meetings, and examinations.
If your circumstances change – for example, if your university loses their right to sponsor Tier 4 visas – your Tier 4 visa may become invalid. The Home Office website has full information on what certain changes may mean for your visa.