The ELO does not exist in isolation. For goods moving from Great Britain into the EU, including France, safety and security data must be submitted via an ICS2 Entry Summary Declaration (ENS) before the crossing, and French customs requires the ELO to reference that filing.
Customs Declarations UK supports ICS2 end to end across all transport modes, so the full UK–France sequence (CDS declaration, ICS2/ENS filing and ELO generation) runs in one place, with no risk of data mismatches between filings.