More than half of employers do not publish salaries in their job adverts, new research has shown.
A study by search engine Adzuna.co.uk revealed that property and healthcare firms are the most transparent about the pay rates they offer, with nine out of 10 adverts listing a wage.
Energy firms and executive job listings are less likely to show salaries, according to research among 500,000 adverts.
Adzuna said some employers are becoming increasingly reluctant to publish pay information, with excuses including fear of disclosing information to competitors or current staff.
Aberdeen, Glasgow and Belfast are said to be the most "secretive" cities, while Southend-on-Sea and Crawley were named as the most transparent.
Flora Lowther, of Adzuna, said: "It is amazing in the 21st century that half of employers still don't put salaries in their job ads, putting candidates off applying for these roles and making the job market less efficient.
"We believe that jobseekers have a right to know what pay to expect."