I can use multiple rows e-invoice for branches or systems?
Short answer
Yes. § 74 ods. 1 letter c) requires the serial number of the invoice and official explanatory notes Financial Administration allow one or more series of numbers, for example by branch or type of delivery. However, each number must clearly identify the invoice. For more than one ERP, use a distinct prefix or other controlled scheme and avoid collisions.
More series
A separate series may have a branch, system or type of delivery.
Clarity
The order number must identify one invoice.
BT-1 without rewriting
To XML include the actual number including the prefix.
Central owner of the rules
The company must be able to explain the number creation and prevent collisions.
Conclusion
More numbers are allowed. The condition is clear identification, consistent BT-1 and collision control.
Act on VAT · Explanatory notes Financial Administration · Peppol BIS
Not legal advice. Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.