Are you clear on the rules for electronic invoicing?

Can we have more than one ‘contracted’ digital postman?

Yes, but it is necessary to distinguish between receiving and sending electronic invoices.

When receiving documents, only one Digital Mail Carrier may be registered for a specific ParticipantID, as specified in the Service Metadata Publisher (SMP) system. Incoming invoices are therefore automatically routed to this Digital Postman.

When sending documents, the situation is more flexible. An entity may have contracts with several Digital Postmen. The selection of a specific Digital Postman depends on the configuration of the accounting system and the contractual arrangements with individual providers. Authentication and technical connection are then handled separately at the level of each Digital Postman.

What should be done if an invoice contains items with different VAT categories, ‘S’ and ‘O’? Do separate invoices need to be issued?

According to the current validation rules of the EN 16931 standard and the Peppol BIS Billing 3.0 specification, it is not possible to combine items with VAT categories ‘S’ (Standard rated) and ‘O’ (Outside scope of tax) on a single electronic invoice.

However, this does not necessarily mean that separate invoices must be issued. In this case, the Slovak Financial Administration allows for a practical solution (an exception): if an invoice contains supplies subject to VAT alongside supplies outside the scope of VAT, the ‘E’ (Exempt from tax) category may be used for items outside the scope of VAT. In field BT-120 – TaxExemptionReason, it should then be stated that the relevant supply is ‘outside the scope of tax’.

This solution stems from the current technical limitations of the standard. The issue is also the subject of a forthcoming revision of the EN 16931 standard, and a more flexible approach to such situations is expected in future, which should subsequently be reflected in Peppol BIS as well.

Which ‘Invoice type code’ should be used for an invoice relating to a received payment?

For an electronic invoice relating to a payment received, code 388 – Tax invoice (An invoice for tax purposes) should be used from the Invoice type code list (UNCL1001).

Before delivering the goods, we receive an advance payment amounting to 100 per cent of the price and issue an electronic invoice for the payment received. The actual delivery of the goods will not take place until the following month. Do we need to issue another electronic invoice upon delivery of the goods, even though there is no outstanding amount to be paid?

If an advance payment was received prior to delivery and an electronic invoice was issued for that payment, a final (settlement) electronic invoice must also be issued upon the subsequent delivery of the goods in the following month. This also applies if, after taking the advance payment into account, there is no outstanding amount and VAT has already been paid on the basis of the electronic invoice for the payment received.

When must the details from an electronic invoice be reported to the tax authority? Does the five-day deadline also apply if the invoice is issued by the supplier themselves – a VAT payer?

If the electronic invoice is issued by the supplier – a VAT payer – themselves, the details from the invoice are reported to the tax authorities at the time of issue.

The five-day deadline applies to cases of so-called ‘self-billing’, where the electronic invoice is issued by the customer on behalf of and for the account of the supplier – a VAT payer. This deadline runs from the date the electronic invoice is issued or from the date on which the deadline for its issue expires.

Will self-billing continue to operate? In such cases, who will be responsible for reporting the data to the tax authorities?

The option of ‘self-billing’, i.e. the customer issuing an invoice in the name and on behalf of the supplier, remains in place. The existing conditions also remain in place, in particular the written agreement between the supplier and the customer governing the terms of acceptance of invoices issued in this way.

In the case of ‘self-billing’, the customer (C4) issues an electronic invoice in the supplier’s name and on the supplier’s behalf and sends it via their Digital Postman (C3) to the supplier’s Digital Postman (C2), who then delivers it to the supplier (C1). It is no longer necessary for the supplier to resend the invoice via the Peppol network. The customer’s Digital Postman will ensure that the data is reported to the tax authorities.

An invoice issued under the ‘self-billing’ scheme is technically identified by a separate code – document type 389 – BIS3 Self-bill invoice.

In order to use ‘self-billing’ via the Peppol network, the supplier must have the relevant documents configured amongst the supported document types for delivery via the Peppol network, in particular 389 – BIS3 Self-bill invoice and 261 – BIS3 Self-bill credit note.

Does the obligation to issue an electronic invoice also apply to supplies made up to 31 December 2026?

No. Issuing an electronic invoice for supplies made during 2026 is voluntary. The date of supply of the goods or services is decisive for the obligation to issue an electronic invoice. The obligation to issue an electronic invoice applies to supplies from 1 January 2027.

Therefore, if a supply takes place by 31 December 2026 at the latest, the invoice may be issued in accordance with the current rules, even if it is not drawn up until 2027. This conclusion follows from the transitional provision in Section 85o(2) of the VAT Act.

If you require our support in the next two months before the launch of electronic invoicing, our experts are at your disposal.