Birmingham City Council has raked in millions of pounds by issuing invalid parking tickets – but motorists will not get a penny back.

Despite the blunder – where only one date was listed on tickets instead of two – affecting hundreds of thousands of drivers, people who paid the #30 or #60 penalty are not entitled to refunds.

In 2005, the last year for which figures are available, 176,382 tickets – the equivalent of 483 a day – were issued in the city by wardens, according to the National Parking Adjudication Service.

If every driver paid the #30 fine within 14 days, that would have brought in #5.3 million. After 14 days, the fine is #60.

It is not known how many tickets are being contested at present. The revelation follows an appeal won by Sanjay Dhir, a Coventry safety consultant, who discovered his ticket was not completed correctly by a traffic warden.

It featured only one date when guidelines to traffic wardens say all parking tickets had to feature the date of the offence and the date of issue – even if the two were the same.

Birmingham City Council is seeking legal advice, but it is believed its tickets now comply with the guidelines.

NPAS, which handles appeals from motorists, said a number of local authorities, including Birmingham, had issued invalid tickets.

The error was highlighted during a High Court case in London last year, when a motorist successfully challenged his fine.

A spokeswoman for NPAS said: "There has been an issue recently with Penalty Charge Notices (PCNs). Since a High Court decision for a case in October, all PCNs must be compliant with the Road Traffic Act.

"There must be two dates shown on it. One must be the date of contravention, that is the date the offence happened, and the other is the date it is issued. You have 28 days from the second date to pay.

"If tickets do not have those two dates, they are invalid.

"These dates may be the same, but sometimes they are not. For example an offence could have happened on February 6, but the ticket may have been issued in the post on February 8.

"This happens in certain cases, for example, if a parking warden's machine is broken, or maybe if the printer is broken. "Also cases may be picked up on CCTV cameras. If you are caught in a bus lane on camera, that ticket would be sent in the post. If people have paid their tickets already, they cannot claim refunds."

A spokeswoman for Birmingham City Council said: "We cannot provide a direct answer on this at the moment.

"Like many local authorities, we followed the original guidelines set. We are now seeking a legal opinion on this particular case."

When asked how many parking tickets had been issued in the city last year and how many had been appealed, a spokeswoman said the figures were not at hand and would have to be researched.

An official at Central Parking System, which is contracted to issue parking tickets in Birmingham, added: "Central Parking System manages the on-street enforcement contract on behalf of Birmingham City Council and we work to their policies and procedures at all times.

"We understand that Birmingham City Council, like many other local authorities, is seeking legal opinion on the Moses v Barnet High Court Judgement."

According to Barrie Segal, who is responsible for www.appealnow.com, a website to help motorists, millions of illegal tickets have been issued throughout the country. He said motorists should consider court action to reclaim fines.

"In 2006, a total of 176,382 parking tickets were issued in Birmingham, that is roughly 3,000 a week," he said.

"I believe that 8.7 million parking tickets have been issued in the whole country and of those, 6.3 million were illegal. NPAS actually wrote to all the councils and said, 'you need two dates' and how Birmingham carried on I do not know."