The Association of Convenience Stores (ACS) has strengthened its call for all energy suppliers to limit backbilling to 12 months.
In a letter to Ofgem, ACS chief executive James Lowman highlighted the threat that an unexpected backbill worth thousands of pounds posed to a small retailer.
More than 116,000 cases of backbills were reported by suppliers in the year between 2012 and 2013.
While the majority of the bills were small, a minority were worth over £20,000 and/ or lasted over five years.
“Many energy suppliers have taken positive steps to reduce the impact of backbills by limiting them to 12 months, as is the case in the domestic sector. However, a number of energy companies still refuse to change their policies and this is simply unacceptable,” Lowman added.
“We will continue to campaign for a one-year backbilling limit introduced by all suppliers, and will not accept any more excuses from suppliers.”
Companies that have committed to a one-year limit include E.ON, SSE, British Gas, EDF Energy, Npower, Scottish Power, First Utility, Good Energy, and Opus.