Do passive filters need a certificate of recognition

No. The reason for this is that passive filters are passivfilters, which realize their filtering function through basic components such as capacitors, inductors and resistors, and do not require an external power supply to drive their operation. As such, they do not produce electromagnetic radiation or electromagnetic interference, nor do they affect other equipment, and therefore do not require certification. Unless passive filters are designed for use in aerospace, medical devices, or other related fields where special certifications and standards may be required, ordinary passive filters do not require a Certificate of Recognition.