Basic information is freely available when looking for companies with no need to register and log in.
You can view detailed information such as addresses and phone numbers if you are registered as an employee with an exhibitor / online exhibitor, as a journalist and you are logged in. Additionally, you will then have access to all services in My Book Fair.
Please find here:
The Association of the German Trade Fair Industry (AUMA) warns of unofficial exhibitor directories that are targeting exhibitors in the run up to trade fairs, offering to provide customers with entries in inferior, sub-standard online directories. Their terms may stipulate long-term obligations to pay several thousand euros, which are generally hidden in the small print.