The European Commission plans to present next week its plan to eliminate differences between domestic rates and mobile calls abroad, making post-travel bill shock a thing of the past.

The commission, through its digital agenda, has set itself a target that, by 2015 the difference between roaming and national telecom tariffs will be almost zero, it said in a statement.

On Wednesday, it will present a proposal to reach that goal, a spokeswoman said.

EU sources told Reuters in May the commission will propose legislation to bring EU mobile phone roaming charges further into line with national tariffs, and set caps in retail data roaming.

Sources said at the time the cap on the cost of roaming voice calls in the EU would be lowered to 24 euro cents per minute from July 2014.

From July 2016, higher roaming costs would effectively be abolished for voice calls, the sources said. Text messages will be capped at 10 cents each until July 2016, compared with 11 cents now.

The EU introduced caps on the rates operators could charge for making calls abroad in 2007, and in 2009 adopted revised rules that cut roaming prices further.

Now, the maximum roaming charge is 35 cents for calls made abroad and 11 cents for calls received while traveling. These 2009 roaming rules will apply until the end of June 2012.

Telecoms providers have challenged EU roaming regulations in the European Court of Justice but lost.

Operators such as Vodafone, Deutsche Telekom, Telefonica and France Telecom complained lower roaming rates have robbed them of huge chunks of revenue, but mobile data company Acision said the transparency that caps provide may be beneficial.

It could even be a revenue opportunity for them, as Acision's research revealed 42 percent of consumers believe that spend limits would encourage them to make greater use of mobile services while roaming, while 41 percent would be happy to pay for real-time notifications, Acision's Jonathan Pearson said.

(Reporting by Nicola Leske; Editing by David Hulmes)