Does the e-invoice have to be human-readable or is XML sufficient?
Short answer
The mandatory e-invoice is structured XML, not PDF. At the same time, however, the invoice must remain human-readable during the storage period. This does not mean that every e-invoice must be accompanied by a PDF, but the company must have a way to display the XML in an understandable form for the control, accountant, audit or tax audit.
Primary document
Contains machine-processable invoice data.
For man
It can be PDF, ERP view or browser.
One truth
The image must be based on XML, not other data.
Long term reading
Even after years, you need to be able to display and explain the document.
Conclusion
The e-invoice does not necessarily have to be a PDF, but it must be legible for a long time; it is best to keep the XML and have a reliable visualization from the same data.
Not legal advice. Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.