Hairdresser's Wage Classification and Calculation of Underpayment

The appellant, a hairdresser who completed a three-year apprenticeship followed by a practical exam, sued for back wages based on an incorrect salary classification, arguing she qualified as a "skilled employee" under the collective bargaining agreement (GAV), which mandates a higher minimum wage than the "semi-skilled" rate the employer paid after her training concluded. The court rejected the claim that her practical exam was equivalent to a formal federal qualification certificate, as the latter requires comprehensive theoretical knowledge, and thus upheld the lower classification; however, the court overturned the lower court's method of calculating total underpayment, ruling that because the contracts established monthly payment terms, the minimum GAV wage must be checked and due for each month individually, meaning overpayments in some months cannot offset underpayments in others.