The company did not turn up for a Labour Court hearing after staff lodged the pay claim yesterday.
However, their union, Mandate, said that the company had told staff they will get the wage hike from the second week of February.
Mandate filed the pay claim on behalf of its 4,000 members at the chain nine months ago.
Although the union was representing less than one third of the staff, it said that the wage increase will apply across the board. It is worth more than €600 to full-time staff, who earn around €23,000 to €24,000 a year.
The union referred the pay claim to the Labour Court after the company failed to attend talks.
Assistant general secretary of Mandate, Gerry Light, said staff had not had a pay increase since December 2007.
"Many retail workers have foregone pay increases over the last few years -- some indeed have taken cuts -- and have given considerable flexibility to their employers," Mr Light said.
"Indeed, even in companies where pay rates haven't been cut, many workers' incomes have declined because of significant reductions to their working hours and they have also been badly affected by rising prices, tax rises and the cuts to public services and welfare payments like child benefit."
However, he said most retail companies remained highly profitable.
He said it is estimated that Dunnes Stores is generating sales in the region of €3.8bn a year and significant profits.
Dunnes Stores did not comment on the development.
More than 3,000 Marks & Spencer and 13,000 Tesco workers got wage hikes worth up to €700-a-year last year.
Debenhams recently agreed to a 2pc pay increase from September 1 after its 1,400 staff accepted plans to extend a pay freeze, which has been in place for two years.