New Zealand-owned fuel company Z Energy has apologised to a small group of "Z Card" business customers for accidentally overcharging.
Z spokesman Jonathan Hill said the mistake affected 16 customers who were overcharged by a few cents a litre for their fuel.
"We've got tens of thousands of commercial customers who have a proprietal Z Card," he said.
"For a small number of them, 16, we made a mistake and gave them the previous week's pricing, but prices have been coming down and as a result they were slightly overcharged," he said.
"We discovered the error discovered the error, apologised for the error, and recompensed them for the price difference," Hill said.
