Retailers will have to pay their 20 year old workers adult rates following a decision by the Fair Work Commission.

However, the workers will need to have been with their employer for more than six months to win a pay rise.

The decision has angered retailers, who say it will risk jobs.

They have called on the federal government to do everything in its power to halt the increase.

“This decision will prove detrimental to both employers and employees,” Australian Retailers Association executive director Russell Zimmerman said.

The commission found that a significant number of retail employees already had at least three years’ experience by the time they were 20.

There was little difference in the work and duties of workers aged 20 and 21.

The discounted rate, 90 per cent of adult rates, for 20 year old workers did not provide a fair and relevant minimum safety net, the commission decided.

The new rates will be phased in over a year, starting July 1, 2015.

AAP