Free calls to 0800 telephone numbers will be extended to anyone using a mobile phone, under plans announced by the regulator, Ofcom.
The vast majority of these calls are charged at up to 21p a minute for mobile users, under current rules.
But Ofcom wants to make these 0800 calls free, as they are from landlines.
A consumer watchdog said many callers already thought these calls were free for everyone and were hit with a shock when their bill arrived.
"This could be particularly frustrating if they have been kept on hold or on the line for a long time when dealing with a complaint to a company, on a number that is described as freephone," said Adam Scorer, of Consumer Focus.
"Many households living on low incomes - who can least afford the charges - only have access to a mobile phone. They are hit hardest by the cost of 0800 numbers from mobiles.
"Changes to make this part of the market simpler are long overdue. We would like to see them brought in as quickly as possible."
A final decision by Ofcom on the proposed new rules will be made by early 2013.
Ofcom said that theproposed changeswere aimed at helping consumers "regain trust" in these phone numbers.
"By making calls to 0800 numbers free from all phones, we will clear up any uncertainty about making calls, especially from mobiles, to the benefit of consumers and service providers alike," said Ed Richards, chief executive of Ofcom.
Ofcom is also proposing to clarify and simplify charges to 08, 09 and 118 numbers, which include information, banking, directory inquiry and entertainment services.
Unless they are using a BT line, callers do not know how much thechargesfor such calls.
Non-geographic numbers can be used to call businesses and government agencies like HM Revenue and Customs and NHS Direct, make payments for services, and vote on television shows.
However, Ofcom said research had shown many people were confused about what non-geographic numbers were for and how much they cost, resulting in a lack of confidence and trust in the services.
As a result, consumers made fewer calls to these numbers, providers were discouraged from using them and there was less innovation that might benefit consumers.