"Text messaging or downloading data via a mobile phone while in another EU country should not be substantially more expensive for a consumer than sending text messages or downloading data at home," Commissioner Viviane Reding said.
"Higher retail charges abroad must be justified by additional cost of operators or they will have to disappear."
Reding suggested operators use a flat rate fee system -- known as "all you can eat," the Times of London reported.
Operators, such as Vodafone and O2 have already lowered rates of text messaging while the consumer is abroad and Tom Phillips, head of Government and Regulatory Affairs at the GSM Association, told the Times, "it's a very new service" and "prices are coming down very quickly."
Reding said that companies have until July to lower rates or face "regulatory interventions."