Since 17 June 2022, phone and broadband firms have been required to give customers contract information and a short summary of the main contract terms before signing up.

The summary must include key information about the price, length of the contract and the terms and conditions if a customer decides to end their contract early.

Customers with disabilities can also request to receive the documents in an accessible format.

Ofcom says these rules “are an important way of helping people shop around with confidence and make informed choices about the right deal for them”.

The regulator opened an investigation into EE on 4 October 2022, as it had reason to suspect it may have failed to comply with these requirements. 

It has since received information giving it reason to suspect that Plusnet – another BT subsidiary – may also have failed to comply with these requirements.

As a result, Ofcom’s investigation will now consider if BT has broken Ofcom’s rules because of suspected breaches by each of these subsidiaries.

Rocio Concha, Which? director of policy and advocacy, said: “It’s extremely concerning that BT is under investigation for potentially failing to provide clear and simple information for new customers at a time when customers under contract with EE, Plusnet and BT are facing huge above-inflation hikes to their bills.

“With the cost of living crisis continuing to bite, Which? is calling on providers to let their customers leave their contracts without incurring exit fees to switch or negotiate a better deal if they face price hikes – regardless of whether or not these increases can be said to be ‘transparent’. Providers should also carefully consider the level of any mid-contract price hikes when many consumers are already under huge financial pressure.”

BT confirmed last week that it will be increasing its prices by 14.4% for the majority of its customers from 31 March, in accordance with mid-contract price increases included in contracts.

A BT Consumer spokesperson said: “We want our customers to be fully informed and we make sales information upfront, clear and transparent. We are fully engaged with Ofcom during the course of this investigation.