Mobile network operators could face fines of up to 10% of turnover if proposals now under consideration at Ofcom become part of the general conditions that govern sales of mobile phones and network access contracts in the new year.
The revised conditions, expected by February, are in response to a rising tide of consumer complaints about mis-selling.
Ofcom said that consumer complaints about unfair contracts, unfair charges, misrepresentation and other issues had risen from 460 in July 2007 to an average of 700 a month by January 2008.
"Ofcom remains concerned over the level of mis-selling in the industry reflected in the number of complaints," an Ofcom spokeswoman said.
Ofcom published a consultation document in March 2008 that listed proposals to combat mis-selling. An Ofcom spokeswoman said today that the proposal to fine those mis-selling would be aimed at network operators in an effort to get them to police their retailers better.
She said Ofcom was still considering how it would deal with independent retailers found to be mis-selling.
She added another consultation about fees and charges complaints, including early termination fees, was nearly finished, and Ofcom would publish the findings and recommendations on this before Christmas.