A number of motorists who have accumulated over 30 penalty points on their licences have not been banned, according to the Institute of Advanced Motorists (IAM).
Under current rules, drivers who amass 12 points in a three-year period can expect a fixed-term driving ban.
However, DVLA figures show that this is not always happening, with one woman from Isleworth accumulating 42 points on her licence – all for failing to disclose a driver's identity – without any further action being taken.
Magistrates can take leniency and choose not to enforce a ban in exceptional cases.
A Warrington man has the second highest points accumulation (36 endorsements) after being caught driving with no insurance six times in under two weeks in February last year.
The IAM also highlighted a number of other problem drivers, including a man from Blackburn who escaped a ban despite having 29 points after being caught speeding eight times in a month.
IAM chief executive Simon Best said: "DVLA and the courts service are upgrading their computer systems to ensure that offence information is shared more efficiently, but this is not due to be in place until October," reported the BBC.
"Drivers must expect that 12 points means a ban or the whole system falls into disrepute."
A spokesman for HM Courts Service, defended the current system, saying: "The vast majority of drivers who get 12 or more penalty points are fined and disqualified from driving.
"Magistrates can use their discretion to not enforce a driving ban if doing so would cause exceptional hardship, such as losing a job or the ability to care for a dependant. A fine will still be enforced.
"Only a very small number of cases are affected by the data-sharing issue and we are working closely with DVLA to improve this."