Check UCAS Track - but if he tries to log on at the stroke of midnight, it's unlikely he'll get through. It invariably crashes.
If his Firm has confirmed his place, no problems!
If not, check Insurance offer.
If he's just missed at his Firm and it was for a Combined programme, they may over the Single Honours. Or vice versa - sometimes Combined/Joint degrees are tougher to get into, sometimes, it's the other way round. If it's in a subject he wants to study & his Firm is the university he really wants to attend, it's really worth considering any alternative offer they make him.
My place has dedicated Admissions phone lines from 8am of Results day - if you need to contact your Firmed university, ring those. Please don't ring the Department unless you're advised to by the Admissions Office. We've had the email asking us to refer any & all enquiries back to the central Admissions phone numbers.
If neither, there will be Clearing phone lines for universities in Clearing. It will be specific degree programmes in Clearing, not a university as a whole.
So you'll need to identify specific programmes at specific universities with vacancies in Clearing, and contact them via the central Admissions numbers which will be on the front page of every university website now, or very soon!
eg: www.royalholloway.ac.uk/studyhere/clearingandadjustment/clearinghome.aspx