The car hire industry has accused the Driver and Vehicle Licensing Agency (DVLA) of "rushing in" new rules for motorists hiring cars.
The changes, which involve the abolition of the paper counterpart, take effect on Monday 8 June.
They mean that anyone hiring a car may have to produce a special temporary code as evidence of their convictions.
The DVLA denied the charge, saying it had been working on the new system "for months".
"The project's being rushed through. It's not brilliant," said Gerry Keaney, the chief executive of the British Vehicle Rental and Leasing Association (BVRLA).
As a result of the abolition of the paper counterfoil, all evidence of driving endorsements and convictions will be held online only.
From now on, motorists are being asked to log on to the DVLA website, and obtain a code, which they may be asked for when they go to hire a car, either in the UK or abroad.
However, the code is only valid for three days, raising the possibility that those going on holiday may have to find internet access.
Guide for motorists
The RAC has previously warned that many people were unaware of the new rules.
A more recent survey by the website money.co.uk suggested that 73% of drivers didn't know they had to produce a code when hiring a car.
And the AA has advised motorists to take their paper counterpart with them, even though it is no longer valid.
But the DVLA denied that using the system is complicated.
"It's very easy to view and share your driving record. Just go to gov.uk and search for 'view driving licence'," said Oliver Morley, the DVLA's chief executive.
He said that motorists could also save their driving records as a PDF file, which they could store on a mobile device.
The DVLA has produced a step-by-step guide to help motorists through the process.
For those who forget to take a code, a phone number is also available, but only between the hours of 8am and 7pm on weekdays, and 8am and 2pm on Saturdays.
Lost counterparts
In many cases, motorists hiring a car are not asked for evidence of convictions. Nevertheless drivers are being advised to contact their hire company before they travel, to see which documents they need to bring with them.
Smaller hire companies, especially based abroad, may be unaware of the changes.
Old-style paper licences - which carry endorsements on them - will remain valid.
The government has defended the new system, saying it will save millions of pounds, and reduce red tape.
Last year, the DVLA had to replace 445,000 paper counterparts. Motorists who lost them were charged £20 for replacements.
However, the British Vehicle Rental and Leasing Association said it would be much better if there were an online IT system which hire companies could use to check convictions themselves.
It, too, has produced advice for motorists.
The new arrangements are valid in Britain only. Northern Ireland has a separate licence scheme.
-bbc
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