The consumer watchdog alleges a popular burger chain has been over-egging the scale of a tree-planting burger promotion and misleading customers.
Grill'd has been accused of overstating the donations made through ''Tree Day Tuesday'', with only a small fraction of burger sales qualifying for the charitable contribution.
The Australian Competition and Consumer Commission chair Gina Cass-Gottlieb said it amounted to a form of "greenwashing", which refers to false or misleading sustainability claims.
''We allege Grill'd misled customers by overstating the extent of the donations it would make and the environmental contributions from its Tree Day Tuesday promotion," she said.
''In fact, only a small percentage of purchases on Tuesdays qualified for a donation by Grill'd because of the detailed conditions of the promotion, which we say were not disclosed or not adequately disclosed to customers.''
