Newcastle City Council has now given residents and businesses on Tyneside an extra two days to submit opinions on the controversial plans.
The 10-week consultation was due to end at midnight on Friday but a website fault meant it appeared to have closed early on Friday morning.
The local authority apologised and said it was “now fixed and working properly”.
“To ensure people haven’t missed the chance to take part we are extending the deadline until midnight on Sunday,” a spokesman said.
More than 14,000 people have already completed the consultation, the Local Democracy Reporting Service said.
Ordered by the government to cut pollution levels at emissions hotspots by 2021, Newcastle is considering two options.
There could be charges for entering a Clean Air Zone (CAZ) or a toll on bridges over the River Tyne, with only newer petrol and diesel cars and ultra-low emission vehicles exempt.
Opponents have said the plans would unfairly disadvantage poorer people unable to upgrade to new, cleaner vehicles.
Bus and taxi firms have also warned of increased fares and the council itself has said charges would not reduce emissions enough.
The Department for Environment, Food and Rural Affairs said local authorities were “best placed to decide how to tackle air quality in their communities”.