Four of Britain's biggest mobile phone companies have removed the fees they charge for relatives to make calls to hospital patients during the pandemic.
Vodafone, 02, EE and Three say they will remove access charges from the premium rate phone lines.
Their move came after Hospedia, the company providing bedside phone services, refused to remove charges.
NHS England called Hospedia's stance "disappointing, during the greatest public health challenge in a century".
With many hospitals restricting visitors to stop the spread of Covid-19, inpatients are increasingly reliant on telephone calls to stay in touch.
For patients unable to use a mobile, such as those with dementia, that often means using a bedside phone supplied by Hospedia.
Last week, the BBC revealed one woman had been charged more than £11 to make a 16-minute call to her elderly mother.
When the trust that runs the hospital attempted to pay for the calls, Hospedia told it the cost would be almost £10,000 a month.
Hospedia has installed premium rate phone lines at 130 NHS trusts.
While calls made by patients to both landlines and mobiles are free, those made by relatives to a patient can be expensive.
The company charges incoming calls 13p per minute and mobile phone companies add an additional per-minute access charge.
EE charges up to 65p per minute while both O2 and Vodafone customers could be charged an additional 55p per minute.
Hospedia had come under pressure to reduce the cost of its calls but, in a statement to BBC News, the company said: "We cannot waive our charges because we need to pay our staff and cover a range of fixed costs, including our network providers."
Instead, the mobile companies have cut their costs.
The first network to announce the move was O2, which said customers would now only have to pay Hospedia's call costs.
"We've removed all our charges for this service.
"We'll also credit any charges back to anyone that has used this service since the start of the pandemic."
Customers do not need to contact O2 as the adjustment will happen automatically, the statement continued.
Vodafone has vowed to match its rival's pledge, telling the BBC: "We will waive the access charge during the coronavirus crisis and refund those charges already incurred by patients."
EE said it was "planning to make these calls completely free, removing both the service and access charges".
The fourth major provider, Three, also confirmed it was removing access charges for patients and would refund customers who incurred them during March.
Hospedia's refusal to cuts its costs was met with a sharp rebuke from NHS England, which awarded the company some of the contracts.
"It is disappointing that at a time when so many people and organisations are doing all they can to support the NHS and the wider national effort to get through the greatest public health challenge in a century, some patients are being charged to speak to their loved ones and vice versa," said NHS England in a statement.