Teenagers who have achieved five good GCSEs can expect to earn an extra £2,260 per year when they start work, according to research.
But one in five employers would not recruit someone without five GCSEs at grade C or better, the Learning and Skills Council said.
The LSC research follows the release of GCSE results on Thursday which suggested teenagers in state schools were improving faster than children from wealthier families who pay to go private.
National figures for 750,000 candidates showed record results this year. One in five - (19.5%) of all GCSE exams was awarded an A or an A*, while 63.3% were given a C grade or better, up from 62.4% last year.
The LSC research showed employers would pay an extra £2,261 per year to new staff with five A*-C grades in their GCSEs compared to those with no qualifications. This was an average of more than £450 in extra pay per GCSE.
Julia Dowd, from the LSC, said the implications of not having the minimum set of qualifications were "becoming more serious".
"It is therefore imperative that all young people take their future in their own hands and remain in or return to learning to gain these essential qualifications."
Dr Mike Cresswell, director general of the AQA exam board, highlighted the differences between school types.
"For the last two years, grade As are going down in the independent sector. In comprehensives they have been going up," he said.
The improvements in results were "due to improved teaching and more effective learning", he said. "If it was just getting easier to get a grade A then the independent graph would be going up as well.
