Last year, South Lanarkshire lost another tribunal verdict to the Educational Institute of Scotland after trying to change contracts unilaterally.
Edinburgh had tried to bring teachers into line with other employees but Colin Mackay, a maths teacher and EIS local secretary, challenged the change.
In its judgment, the tribunal admits "there was great force" in the aim of "harmonising teachers' disciplinary and dismissal procedure". But changes to contracts could not be imposed.
Ronnie Smith, EIS general secretary, said it was unfortunate council tax payers had to foot the bill for a case that was effectively lost a year ago. The city, which is pursuing a related case in the Court of Session, is "considering the judgment".