Before the line can carry passengers, the German section of the route will need to be certified in accordance with German Federal Regulations on the Construction and Operation of Light Rail Systems (BOStrab), and the Stuttgart-based Technical Supervisory Authority for Tramways (TAB) is overseeing the certification process. All types of tram currently in use with BVB will be tested during this phase.

Swiss customs officials are also using the test phase to gain experience of border controls on the new line. Passengers will be able to travel freely across the border, with German customs officers carrying out random checks.

The SFr 104m ($US 109m) extension is due to open on December 14, when BVB will offer free rides along the entire length of Line 8. BVB will operate a 15 minute service on the extension on weekdays, with every second tram on Line 8 continuing to Weil-am-Rhein. The new fleet of Flexity LRVs currently being delivered to BVB by Bombardier will be deployed on the extended route.