If you are travelling to Germany you are required by German law to pay all staff a minimum wage of at least €8.50/hour. You must register your journey with the German authorities in Cologne, including a new requirement to declare your expected number of trips to Germany. The declaration form can be downloaded from: http://ow.ly/PAzzh. You must use form 033037 (mobile); or form 033038 (mobile) if you use temporary staff. The form must be filed with Bundesfinanzdirektion West in Cologne by fax on +49 221 964 870.

Germany implemented the Act on 1 January, 2015. It applies to all industries so includes truck drivers and crew members. The Act applies to any journey that takes place to, from or in Germany but does not apply to transit journeys.

UPDATE: 17/09/15:
Please note that the fax number for the notification of exclusively mobile activities has changed.  With immediate effect, when notifying Customs of exclusively mobile activities (form 033037E (mobile activities), and form 033038E (mobile activities)) by fax, please only use fax number +49 221 964 872.