Retail workers and teachers top a list of people unhappy with their pay.
A study by jobs site Adzuna found that charity and social workers were also among those not happy with their salary.
The happiest workers were those in human resources, consultancy and construction.
The survey of 1,000 workers found that two out of five believed they were paid less than their colleagues.
Construction workers are among the happiest, the study found (David Davies/PA)
Doug Monro, co-founder of Adzuna, said: “British workplaces are rife with uncertainty over pay. An ingrained lack of transparency over earnings and salary bandings has created a culture of conviction that others must be paid more than us.
“Combined with a lack of knowledge of what our own skills are worth to employers in today’s job market, this spells a recipe for disaster for ambitious career builders.”
The report was published to mark Adzuna’s ValueMyCV, which calculates how much someone is worth based on their CV.