The chaos following the scrapping of paper tax discs came under fire from MPs on Monday.
The Driver Vehicle and Licensing Agency website was overwhelmed last week and its phone lines jammed when thousands struggled to pay their vehicle excise duty online.
The all-party Transport Select Committee said motoring agencies must “work harder to deliver a better service for all”.
Chairman Louise Ellman said; “The recent problems demonstrate the importance of responding to change, having a clear communication with the public and an effective contingency plan to maintain confidence.”
Under the new set-up payments are recorded electronically and linked to an automatic number-plate recognition system.
The AA said it told the committee that the DVLA computer system was inadequate.
The report also criticised the sale by the DVLA of motorists’ personal data to parking enforcement organisations. Firms can obtain details of owners for £2.50 from the DVLA.
Pressure group NoToMob told the committee that Government reforms had seen “rogue clampers reincarnated as rogue ticketers”.
The committee said it wanted drivers notified if their data was sold on.