With the annual scramble over places now under way they appealed to teenagers to think seriously about what they accepted - and may later reject. If students decide they have chosen the wrong course and then drop out they could jeopardise any further mandatory funding from their local education authority.
Latest figures from the Committee of Vice-Principals and Chancellors reveal that around 40,000 people have quit university courses for financial or academic reasons.
The Association of University Teachers claimed that many higher education institutions were now relying on more students dropping out in order to be able to offer places to this year's A-level batch.
About 396,000 people are currently chasing an estimated 270,000 places at universities and colleges - a 1.5 per cent increase on last year.
Many are now in clearing, the system in which students who missed their first university choice are matched to remaining higher education places.
Offers of places on the popular single-subject humanity courses and perennial favourites of medicine, dentistry and law are likely to be few, particularly at Nottingham, Exeter, Durham, Bristol and Edinburgh universities - the current favourites. But once again there will almost certainly though be a glut of places on engineering and science courses.
David Triesman, general secretary of the AUT, said: "Students who enter the clearing system are being forced to make rushed decisions based on inadequate information. It's not surprising that many make mistakes and regret opting for courses or institutions they did not really choose to attend."
The CVCP, Standing Conference of Principals, Association of Metropolitan Authorities and Association of County Councils, alarmed by the rising number of drop-outs, are now working on guidelines for students to be published this autumn which will explain how to withdraw or change course and about grant entitlement.
If students drop out before 20 weeks of their course they will be able to re-apply for a grant the following year, after 20 weeks they run the risk of being disqualified for mandatory grant.
Julia Bennett, an AMA education officer, said: "We would encourage any student to suspend rather than withdraw completely from a course if they are unhappy. "
Jess Enderby, assistant executive at the University and Colleges Admissions Service, said: "Students must be absolutely sure that the course they are negotiating for is one that is suited to them. The increase (in drop-outs) does worry us and in many ways it is worse than re-sitting exams or taking a year out and having another go."