Transport for London may refuse to accept congestion charge payments from unofficial 'copycat' websites which charge users an additional premium.
TfL says unofficial 'copycat' websites can mislead customers, who often end up paying more than they need to for the congestion charge. Some drivers pay up to an extra £8 for what TfL calls "non-existent additional services".
In January, the Advertising Standards Authority upheld three complaints against the website paylondoncongestion.co.uk and ordered the website to make changes.
The move follows efforts to persuade search engines to downgrade the websites and give TfL's official payment page more prominence.
Transport for London is considering scrapping text messages as a payment method for congestion charges.