Abolition of the driving license paper counterpartMotorists trying to access a new system for hiring a car have been experiencing problems with the DVLA website.
A number said the system - which does not apply to Northern Ireland drivers - was not working properly, while some car hire firms had to cope with queues.
The changes, which involve the abolition of the paper counterpart, take effect on Monday 8 June.
But the DVLA said that more than 20,000 drivers had managed to access the site without difficulty.
From now on, motorists hiring a car may have to produce a special temporary code as evidence of their convictions.
The DVLA said it had been working on the new system "for months".