Short answer
An e-invoice, or structured electronic invoice, is an invoice in a machine-readable format (XML) that follows the European standard EN 16931 (LVS EN 16931 in Latvia). Software can read and book it automatically without retyping. An ordinary PDF invoice sent by e-mail is not an e-invoice in this sense.
The key difference from an ordinary invoice
An ordinary invoice — paper or PDF — is meant for a person to read. An e-invoice is meant for a computer: all the data (supplier, buyer, goods, amounts, VAT, due date) sits in structured fields in an XML file, so the recipient’s system can read and book it automatically.
Standards
In Latvia a structured e-invoice must follow the European standard LVS EN 16931-1:2017 and the technical specification LVS CEN/TS 16931-2:2017. In practice the Peppol BIS Billing 3.0 format is widely used — see what is Peppol.
Why e-invoices pay off
- No retyping — the data goes into accounting automatically.
- Fewer errors and faster payment.
- Easier VAT control and reporting.
Is it mandatory for me?
E-invoices are already mandatory when invoicing public bodies, and between businesses they become mandatory from 1 January 2028. Details: when e-invoices become mandatory in Latvia.