STL pays great attention to covering the relations between companies and their clients through the Customer Services (CAU), which provides specialised human resources and technological solutions.

STL permanently supervises and controls the infrastructures and equipment with the aim of strengthening security and avoiding undesired incidents that may affect the normal running of the business.

In the case of breakdowns or sudden problems, the CAU reduces in so far as possible the time needed to substitute or repair equipment and to solve incidents.