Orange breached advertising rules by saying that a broadband deal offered "unlimited" calls and downloads, the UK's advertising watchdog has said.
Orange said the omission was the result of a production mistake
The Advertising Standards Authority found calls were limited to a "fair usage" of 1,000 minutes a month - which was not stated in the magazine advert.
Downloads were also subject to a limit, depending on network availability.
Orange said the details had been omitted from the small print in the advert because of a production error.
The phone firm broke rules by failing to mention "fair usage policies" that affected both phone calls and downloads , the ASA said.
"We concluded that, because it did not include a reference to Orange's fair usage policies for both the Talk service and the unlimited downloads, the ad was misleading," said the advertising watchdog.
The authority said that claims in future about unlimited calls had to include details of the firm's fair usage policy.
Orange said that, in March, 1.86% of customers had used more than the 1,000 minutes per month of call time and 1.09% had gone beyond the download cap.