A clause within an employment contract describing non-statutory benefits as both "voluntary" and "revocable" was ambiguous and not capable of excluding the possibility that an annual Christmas bonus could become a contractual benefit via "custom and practice".

In this case the employer had paid a Christmas bonus between 2002 and 2007 without expressly stipulating that such bonus was being paid ex gratia. As a result of the financial crisis, the employer did not pay the bonus in 2008 and in doing so relied on a general clause in the employees' contracts which stipulated that all non-statutory benefits and bonus were voluntary and could be revoked at any time.

The Federal Labour Court found in favour of the employee and noted that in order to prevent employees gaining contractual benefits via "custom and practice" the employer must make it clear that benefits and bonus are being paid on an ex gratia basis. In the present case the benefits were described as both "voluntary" and "revocable" and the court was of the view that this was too ambiguous (i.e. something can either be voluntary or revocable but it cannot be both) and that the ambiguity should be judged in the employee's favour.