If you want to transport letters commercially, you need a postal licence. You can apply for one from the Federal Network Agency for Electricity, Gas, Telecommunications, Post and Railway.

If you have indications of possible infringements of cartel law you can send them to the Bundeskartellamt as a submission or complaint.

As a company in the main and ancillary construction sector, you can use the prequalification procedure to identify yourself to public contracting authorities and be entered in the official register of prequalified companies (PQ-VOB).