On 21 September 2015, the Spanish Supreme Court handed down a significant ruling which dismissed a company's appeal regarding the inclusion of a clause in its new personnel employment contracts. Such clause establishes that "any kind of communication related to this contract or to the employment relationship, may be sent via SMS or via email, by means of a text message or document attached thereof, according to the data provided by the employee on the effects of the contract". Additionally, the clause also states that the data provided by the employee in the employment contract, must be notified to the company in a reliable manner and as soon as reasonably achievable. The Spanish Supreme Court ruled that the delivery of such data shall never be mandatory although it can always be provided voluntarily by the employee. Hence, the worker's "voluntary" consent to provide this information shall not be included as a standard clause in the employment contract, as the worker is always considered as the weaker party and, whose consent in this sense may not be considered as totally free and voluntary. Consequently, such standard clause is considered to be unfair and unenforceable and shall, therefore, be excluded from any employment contract. Please note that, in any other circumstances, according to the Spanish Protection Data Act, such data as the worker's personal telephone number and email address, shall always require his consent.