If an invigilator suspects you of cheating, they will take away your exam paper and issue you with a new one. They will complete an Exam Incident Form and this will be sent to your faculty along with any evidence such as photographs.
Sometimes a problem won't be noticed in the exam but may be raised later.
Once your faculty receives the exam incident form they will investigate. This usually involves a panel meeting similar to a plagiarism panel meeting. At the meeting you will be asked questions about what happened in the exam and have the chance to tell your side of the story.
If you have been invited to a meeting to discuss a suspicion of exam cheating, get in touch with Just Ask for advice about how to prepare. You can also take an adviser into the panel meeting with you for support if you would like.
After the meeting, the panel will decide what action, if any, to take. There are a range of options available which include things like keeping the matter on file for future reference, awarding lower marks or awarding 0 marks. They will also decide whether to allow a resit and whether or not this will be capped at the minimum pass mark.
The panel decision does not become final until it is ratified by the faculty exam board and at this point you have the right to appeal against it.