More than 20 councils across England are removing pay and display parking machines and asking people to pay using an app instead.
Eight councils – all in London – have already removed all their machines, while 14 have removed some.
Councils say this saves money by reducing the risk of theft and avoiding the need to upgrade machines.
But charities say the changes are “disastrous” for people without a smartphone, especially the elderly.
A growing number of councils are getting rid of traditional pay and display meters because mobile operators are switching off the 3G networks used to process card payments on older machines.
Councils say there is also a risk of theft from cash machines, while there are costs associated with collecting cash.
The BBC collated figures for 244 councils across England, which are responsible for parking. Out of the 242 councils which had information on their website or responded to requests for comment, eight had removed all their pay and display machines, while 14 had removed some.
Half of all London councils – 16 – have removed some or all of their machines.
Councils which have already removed all their machines include Bromley, Enfield and Kensington and Chelsea.
Others, including Brighton and Hove, and Slough, have removed some machines or are in the process of doing so. Oxford is also moving towards going cashless at all of its car parks.
As well as payment via app, many councils also offer the option to pay over the phone or in a local shop.
Out of the councils in Scotland, Wales and Northern Ireland which responded, none had removed pay and display machines.
Nearly a fifth (19%) of drivers say their council has either scrapped machines or is consulting on doing so, according to a survey of 1,900 drivers by the RAC.
The survey found 59% of respondents felt angry about the idea of machines being removed, with the figure rising to 73% for those aged 65 and older.
Customers also complain they have to download several apps for different areas, with at least 10 apps used by councils across the country.
Caroline Abrahams, charity director at Age UK, said there should always be an offline payment option to avoid excluding older people and others without a smartphone.
“If you are an older person who is reliant on your car for getting around but you have no means of legally parking it near to where you want to go then you may be left feeling there is little point going there at all, and that would be very sad for anyone affected, and very bad news for businesses too.”
Labour MP Clive Betts, who chairs the Commons Levelling Up, Housing and Communities Committee, urged the government to act to prevent people without a smartphone being unable to park.
“We’ve got to recognise that being able to park is a public service and people need to be able to access it easily,” he told media
In April, Levelling Up Secretary Michael Gove wrote to councils in England telling them they must ensure parking services remain accessible to all.
A Department for Levelling Up, Housing and Communities spokeswoman said: “Councils should determine what is best for their own area and have a duty to ensure that they do not discriminate in their decision-making against older people or those with vulnerabilities.”
A spokesperson for the Local Government Association, which represents councils in England and Wales, said: “The removal of the 3G network is posing considerable challenges to some councils who operate physical parking meters.
“This change, along with other customer trends, has led to councils digitising parts of their parking services.”