@Thefatbutteredpig - there is an agreement between UCAS and the exam boards whereby the results are sent to UCAS and then on to universities on the Friday before A level results day.
University data systems have a direct link to ucas data and this updates overnight. We can view applicants' data through our own info systems (you may have heard of SITS and e:vision, which most universities use).
I work in a department and can view results in bulk, eg all firm offer holders, all insurance offer holders, all overseas.
We also have a 'back door' directly into UCAS where we can view applicants' data on UCAS's own platform.
UCAS call advisors: you mean those working at UCAS? I don't know, I'm afraid.
As mentioned by a pp, there is an embargo on communicating results until 8am on exam results day. We cannot communicate results - directly or indirectly - to anyone at all. If there is a breach on this agreement, it is taken very seriously and affected universities are hauled over hot coals.
Anyone in universities involved in Confirmation and Clearing (that's the term for the whole week's activities) has to undergo embargo training each year to ensure we understand the importance of staying schtum, ensuring no inadvertent leaks from ill-planned mailings, and making sure our info systems are secure.