Around 300,000 teenagers across the country will collect their A-level results today.
Students in England, Wales and Northern Ireland will head to schools and colleges to find out their grades and learn if they have secured a university, apprenticeship or training scheme place.
Last year, A-level pass rates fell for the first time in 32 years, while the proportion of exams awarded the very highest grades rose. In total, 98% of exams scored at least an E grade, down by 0.1%.
Commenting ahead of the results, Chris Keates, General Secretary of the NASUWT, the largest teachers' union in the UK, said the publication of the results was "against a backdrop of uncertainty" due to recent qualification reforms and claims about inaccurate marking and standards.
"Every year young people and teachers who have worked hard throughout the course see their efforts undermined by those who wish to detract from the achievements of our public education system which delivers, year on year, world-class standards of education," said Mr Keates.
The tens of thousands of would-be students without a university place are likely to enter clearing - the annual process which allows them to search and apply for courses that still have vacancies.
Last year, 512,000 people secured a place at university or college through UCAS, with 61,300 students being accepted through clearing.
Many student will defer their places to head off on gap years, with some Association of British Travel Agents (ABTA) members specialising in gap year travel reporting increases of more than 10% in bookings over the last year.
A study by ABTA found Australia is the most popular destination, followed by New Zealand and the USA.
Nikki White, for ABTA, said: "Thousands of young people will be heading off on a gap year which for many will be one of the most memorable and rewarding 12 months of their lives.
"However, foreign travel can offer a range of challenges and it is important that gap year students prepare carefully if they are to travel safely and also get the most out of their experience overseas."