What is EndpointID in e-invoice?
Short answer
EndpointID is the e-mail address of the seller or buyer. In the Peppol network, together with the schemeID attribute, it is used to uniquely identify the participant, to find his document capabilities and to route the document correctly. According to the rules of the Slovak Peppol authority (PA SR), scheme 0245 and a ten-digit VAT number without the SK prefix are used for Slovak entities. If the address is incorrect or not registered on the network for the requested document type, the invoice may be undeliverable, even though the XML itself has passed content validation.
The provider takes over the document
The sender hands over the e-invoice to their certified delivery service provider.
The network will search for the recipient
According to the participant identifier, the recipient's registration, supported documents and his delivery point are searched.
The target provider is determined
The network metadata will determine through which provider and by what process the document is to be delivered.
The document will arrive at the addressee
Successful syntactic validation of the EndpointID does not by itself confirm recipient registration or successful delivery.
Conclusion
Not legal advice. Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.