The Association of Convenience Stores (ACS) is gathering details of retailers' experiences to present to the Low Pay Commission.
ACS chief executive James Lowman said: "Each year we give written and oral evidence to the Low Pay Commission that reflects how the industry is coping with the NMW, and support from local shops is vital in building our case for a freeze in minimum wage."
The Association is asking retailers to answer a few questions online. "By spending a few minutes adding their personal experiences to our evidence base, retailers will be able to have a real impact on the decision-making process of the Commission," Lowman added.
Members of the Commission, which makes recommendations to the government, learned first-hand of the effects on employment and profitability of the NMW during a visit to Tates Spar in Wrexham.
Tates managing director Geoff Hallam said afterwards: "Variable rises over the past few years have made it difficult to predict the changes. We hope that the Commission will take this into account when setting their recommended rate at the end of the year."