Shop employees are set to feel the fallout of new wage agreements, costing between $10 million and $200 million a year,  as retailers minimise their impact by tightening rosters, automation and simplifying processes.

Retailers such as Woolworths, Coles, Bunnings, Big W, Kmart, Super Retail Group and Noni B are facing materially higher wages bills after signing new enterprise agreements that restore weekend and evening penalty rates and casual loadings, which were traded away for higher base rates in the past.