Vodafone breached PAYG obligations for more than four years, regulator believes
Ofcom has announced it has "reasonable grounds" to believe that Vodafone breached its obligations to pay-as-you-go customers.
The regulator has been investigating the telecoms giant's alleged sale of PAYG services to a group of customers who were not provided with the service.
It said that following the probe, it believed that Vodafone had breached its obligations when selling PAYG services between May 2011 and September 2015 and issued bills that did not represent the true extent of the service it actually provided.
Vodafone now has the opportunity to respond to Ofcom's findings before the regulator makes its final decision, which could include a financial penalty, within a few months.
A Vodafone UK spokesman said: "We note Ofcom's statement on this investigation, with which we have been cooperating fully.
"We will be reviewing the Ofcom report in detail before deciding what representations to make."
Ofcom is also currently running a separate investigation into Vodafone's complaints handling procedures.
Last month Vodafone became the most complained-about pay-monthly mobile provider after issues with a new billing system sent customer grievances surging.
Ofcom said complaints made to Vodafone surged to 32 per 100,000 customers in the final three months of 2015, up from 20 in the previous quarter.
This made it the only provider to have more complaints than the industry average of 10 per 100,000 customers.
It comes after Vodafone moved customers over to a new billing system at the end of last year.
Ofcom said complaints received about Vodafone related to billing, pricing and charges, as well as complaints handling and fault, service or provision issues.