Every operator in the chain that handles the product as organic needs to be certified, and the certificate scope has to name both the products and the activity. For a frozen vegetable that means the grower, the processing and freezing site, any separate packer or blender, and the importer, each holding a current certificate issued by a recognised control body under Regulation (EU) 2018/848 on organic production and labelling of organic products.
A certificate that names the site but not the activity you are buying is a gap. A freezing site certified for IQF vegetables but not for blending cannot supply a certified organic blend, even if all components are organic.
For product from outside the EU, the import side needs its own attention. Organic goods are imported under the arrangements in force for the third country and control body concerned, and each consignment travels with a certificate of inspection issued through the EU electronic system for organic trade. That document, and not a supplier statement, is what makes the consignment marketable as organic. The arrangements and the list of recognised control bodies change, so verify the current position for your origin before contracting rather than after loading.
Three operational requirements follow for a plant that runs both organic and conventional product on one line. Documented segregation of raw material, work in progress and finished goods. A cleaning and flush procedure between runs, with records. And traceability that can reconstruct an organic lot from field to pallet, which is what an inspection actually tests.
One misconception is worth stating directly, because it costs money: organic certification governs the production method and the permitted inputs. It is not a residue guarantee, and organic lots are assessed against the same MRLs as conventional ones. Most organic buyers additionally apply an internal action level near analytical detection level, with an investigation procedure rather than automatic rejection.
Labelling adds the last step: the code number of the control body and, where the EU organic logo is used, the place of farming indication.