Hi Iwan, I think the outright 'fail' rate is something like 1 or 2%, assuming you submit your thesis. Of course, there is a range of other things that can happen, including various types of corrections, resubmission or the award of an MPhil instead of a PhD - it's worth looking on your uni website to see which types of outcome they use. But assuming you pass the various stages along the way (like the one you have just passed - well done) and manage to write and submit your thesis, failing should not be something you expect. I don't think it is normal to repay a stipend either.