Mohammad Riaz, 53, was stripped of his hackney carriage and private hire licence by the council after he failed to report the cyclist incident to the licensing authority and a separate incident where he left his vehicle while he went to Sainsbury's.
By chance officers carrying out an operation in the town centre on Monday, July 13, last year witnessed Riaz knock a cyclist from her bike at the Clarenden Road rank, by opening his car door into her path.
The woman was unhurt, but Riaz received 12 penalty points under the council's system for failing to report the incident to the Town Hall.
Riaz received a further eight penalty points for parking at the Albert Road South taxi rank on Friday, April 3 this year while visiting Sainsbury's, which prevented another taxi access to the rank.
Both offences meant Riaz reached the council's 20 penalty point limit and his licence was revoked.
Riaz, of Langley Way, Watford represented himself during an appeal to get his licence back at Watford Magistrates Court on Thursday.
He told the court the cyclist ran into his taxi rather than him opening his door.
Riaz also maintained he was only on the Albert Road rank for a few minutes while he popped into Sainsbury's, although council officers recorded it as being nine minutes.
His appeal was dismissed after hearing evidence from three council officers and the member of the public who was knocked off her bike.
The council, represented by Mr Asitha Ranatunga, was awarded a contribution of £800 towards its costs.
The council's licensing manager Jeffrey Leib said after the verdict: “The penalty point scheme exists to ensure drivers are clear about their obligations to the public and in relation to their licence.
“We are pleased that the magistrates' court supported us on this occasion.”