One in five local councils have failed to convert all their parking meters to accept the new £1 coin. With the old £1 coins fast disappearing (and not legal tender from 15 October), some motorists have resorted to desperate measures, such as leaving coins on the dashboard with a note about the meter to avoid being ticketed.

A freedom of information request by the AA found that 74 of 340 UK councils – 21.8% – with responsibility for car parks with coin-operated ticket machines, still haven’t converted all of them. The AA has warned that a day trip to some of the UK’s major cities during the summer holidays may leave visitors struggling to pay for parking and at the mercy of local authority enforcement.

In Devon, the AA figures suggest that not a single parking meter has been converted, but a full changeover is promised by August. The Forest of Dean in Gloucestershire and the Scottish Borders region have also reported zero conversions. In Oxfordshire the figure was just 5%, with a full changeover not expected until September.

If the machines are unfit for purpose because they can’t take legal tender, that’s the council’s problem Edmund King, AA president

Edmund King, president of the AA, said: “Problems with converting ticket machines are not drivers’ fault. If councils are having difficulties because their contractors are under pressure, or because replacement machines or software have yet to be delivered, the driver shouldn’t be blamed. If the machines are unfit for purpose because they can’t take the legal tender for a parking charge of £1.60 or £3.60, that’s the council’s problem.

“[They should] either make the car parks free to use until the machines are converted or provide some kind of online means to pay within a reasonable time, without having to waste time or pay extra to sign up to cashless parking systems that occasional visitors may never use again.”

The AA is encouraging consumers to write to their MPs and complain via social media.

One Guardian reader from Greenwich, south-east London, wrote to us about her frustration. “Our local parking meters (London boroughs of Greenwich and Lewisham) still can’t accept the new coins. They want you to use the old ones, which we all used up as advised by the Royal Mint. They’re now quite hard to find.

“The meters are sub-contracted to a variety of bodies, but we are being encouraged to use their apps and go cash-free. Surely that should be a choice? Many customers don’t have smartphones. And should people without one be asked to ring with their financial details in a public place? Surely it’s up to meter providers to make it possible to pay with legal tender?”

The AA is worried that some councils have taken the opportunity to introduce new-style ticket machines that require drivers to enter their vehicle’s registration number, saying: “These are the bane of the elderly, people in a hurry or people who may have left their reading glasses in the car, and others. All unfairly run the risk of a penalty charge notice for making a mistake rather than trying to dodge payment.”

Cheshire East is one council that has introduced these machines in its car parks in Macclesfield.

“We realise that upgrading the machines is taking time, and work continues to ensure parking equipment can accept the new £1 coin,” the British Parking Association says. “The BPA is encouraging members who have payment equipment to ensure the new £1 coin can be accepted and in the vast majority of cases we are confident that this will be the case.”

Rather unhelpfully, it added: “The public is advised to ensure they carry a range of coins to pay for parking while this transition takes place.”