Subheading 9002 20 of the Combined Nomenclature covers mounted optical filters intended for use in optical instruments, cameras, projectors, microscopes, spectrometers, laser systems and other scientific or industrial apparatus. An optical filter is an optical element that selectively transmits or reflects electromagnetic radiation within a defined range of wavelengths. Classification under this subheading applies to filters already mounted in a mechanical housing — such as a threaded ring, bayonet mount or rectangular frame — ready to be fitted to an instrument or piece of apparatus. The subheading covers a broad range of products: colour and correction filters for photography (ND, UV, circular polarising CPL, skylight), narrow-band interference filters for spectroscopy and fluorescence microscopy, infrared (IR) and ultraviolet (UV) filters for cameras and surveillance systems, laser filters (notch, bandpass) for scientific laboratories, and heat-absorbing and anti-reflection filters for projectors. Unmounted raw filter elements without a mechanical housing are classified under heading 9001. Optical filters that form an integral and inseparable part of a complete instrument are classified together with that instrument. Classification follows the General Rules for the Interpretation of the CN and the notes to Section XVIII and Chapter 90.

Importing mounted optical filters under subheading 9002 20 into the European Union requires compliance with the Union Customs Code (Regulation (EU) No 952/2013). The importer must hold an EORI number and submit a customs declaration with the correct 8-digit CN code. Optical filters as precision components are not generally subject to the General Product Safety Directive (2001/95/EC) as standalone parts intended for integration into apparatus. An exception applies to high-power laser filters of safety class 3B or 4, for which the requirements of EN 60825 on laser safety may apply. Filters for military or dual-use applications, such as laser filters for targeting or guidance systems, may require an export or import authorisation under EU Regulation 2021/821 on dual-use items. Documents required for customs clearance include: a commercial invoice with a technical description (filter type, spectral range, housing size), transport document (CMR, AWB or B/L), technical specification, and if applicable, a certificate or declaration of origin for preferential duty rates. Current MFN rates should always be verified in the European Commission's TARIC database.

Mounted optical filters under subheading 9002 20 belong to the category of precision optical components for which the European Union maintains relatively favourable tariff conditions. Under the WTO Information Technology Agreement (ITA) and EU autonomous tariff suspensions — regularly updated by Council regulations — a zero duty rate may apply to products with a defined scientific or industrial purpose. MFN duty rates for specific 8-digit CN codes within subheading 9002 20 must be verified in the European Commission's TARIC database, as rates may differ by product specification. Preferential duty rates may be available under EU FTAs with Japan (EPA), South Korea, Canada (CETA), the United Kingdom (TCA) and Switzerland, as well as under the GSP and GSP+ schemes for developing countries. To claim preferences, a valid proof of origin must be provided. The importer should check in TARIC for any applicable anti-dumping duties or other trade restriction measures for the specific product and country of origin. VAT at the rate applicable in the country of import is charged on the import value in addition to any customs duties.

Subheading CN 9002 20 covers mounted optical filters used in scientific instruments, photography, and industry. This includes UV filters, IR filters, polarising filters, interference filters, neutral density (ND) filters, and bandpass filters. Filters must be mounted – unmounted ones are classified under 9001 90. Optical filters for cameras (e.g. threaded lens filters) are classified here, not under heading 9006. Filters used in optical telecommunications may be subject to dual-use export controls.