An EORI (Economic Operators Registration and Identification) number is a UK/EU trade registration required only when shipping under EXW (Ex Works) or FOB (Free on Board) terms with your own freight forwarder — under DDP (Delivered Duty Paid), the supplier handles customs clearance and no EORI is needed. Registration itself is quick, roughly 5–10 minutes online.
EORI is one of the practical gating factors that pushes first-time importers toward DDP: skipping EXW/FOB (and the EORI step, and the freight-forwarder relationship they require) trades some landed-cost savings for simplicity.