The PI Certification Office (PICO) issues
PROFINET/PROFIBUS/PROFIdrive/PROFIsafe/PROFIenergy certificate. The certificate is valid for three years. Certificate renewal (update without retest) is free of charge.
The price of certificate is independent from the price of the certification tests, it is paid directly to the PICO.
Application forms for the certificates are available at the PI pages.