§ 4b

How does e-invoice work for a VAT group registered under § 4b?

Short answer

For group registration under § 4b, transactions with third parties must be distinguished from internal transactions between members of the group. Supplies between members of the same VAT group may fall outside the scope of VAT and may not create an obligation to issue an invoice under § 72. If members exchange documents voluntarily through Peppol, they must still comply with the technical rules for the participant ID, tax category O and the prohibition on stating VAT identifiers under rule BR-O-02.

Section 4b

VAT group

Members act separately in the VAT regime vis-à-vis third parties.

tax identification number

Routing

The Participant ID can be based on the TIN of a specific member.

VAT number

Joint registration

The tax field cannot be mixed with the technical address.

BR-O-02

Without VAT ID at O

In the case of an out-of-scope document, the VAT identifiers of the parties will not be entered.

Detailed explanation

A VAT group has a common VAT registration number, but individual members may have their own tax identification numbers and their own technical identifiers for routing. This creates a practical combination: for tax data, the group’s common VAT registration number may be relevant, but for Peppol routing, the exact participant ID according to scheme 0245, based on the tax identification number, is used. However, if the document uses category O – outside the scope of VAT – the Peppol rule BR-O-02 prohibits the inclusion of the Seller VAT identifier BT-31, the Seller tax representative VAT identifier BT-63 and the Buyer VAT identifier BT-48. Therefore, it is not possible to simply copy the same group VAT registration number into both fields.

As set out in the law and technical rules

Section 4b of the VAT Act governs group registration. Section 72 deals with the obligation to issue an invoice and Section 85o with electronic invoicing. The technical restriction for category O stems from the Peppol BIS rule BR-O-02.

Practical examples

Member A invoices a third party; the payer’s scheme and mandatory e-invoicing apply in accordance with the conditions of the Act.
Member A and Member B exchange a document internally that is not subject to VAT; if this is done via Peppol, category O must be used without VAT ID fields.
Routing can be based on the member’s participant ID, even if the VAT group shares a common VAT number.

Common misconceptions

“The same VAT group ID is automatically included in every internal invoice.” Not in the case of category O and rule BR-O-02.
“The participant ID is the same as the group’s VAT number.” No. For Slovakia, schema 0245 and the VAT number are used.
“The group’s internal documents must always go via Peppol.” Not always. It is necessary to assess whether a statutory invoicing obligation arises at all.

Conclusion

For group VAT, the tax status of the group, technical direction via VAT number and Peppol rules for documents outside the subject of VAT must be separated; mechanical copying of the VAT number into all fields leads to errors.

Legal and technical basis

Act No. 222/2004 Coll. on VAT, Section 4b
Act No. 222/2004 Coll. on VAT, Section 72
Act No. 222/2004 Coll. on VAT, Section 85o
Peppol BIS Billing 3.0, BR-O-02

Official cases from the Slovak Financial Administration’s FAQs

The following questions and answers are taken from the current July FAQ from the Financial Administration and have been assigned to this topic. Grouping the cases prevents the creation of duplicate pages, whilst retaining the full answer and the exact wording of the question.

Example No. 52: Electronic invoicing in the context of group registration under Section 4b of the VAT Act 1. Obligation to send: Is there a legal or technical obligation to send invoices (documents) issued for supplies between members of the same group (Section 4b) via the Peppol network, if these supplies are not subject to tax and do not give rise to an obligation to issue an invoice under Section 72 of the VAT Act? 2. Identification and routing: If group members decide to exchange these documents voluntarily via Peppol, is it correct to assume that invoices will be routed on the basis of the individual members’ unique VAT numbers (as the Participant ID), even though the same group VAT number will be entered in the fields for the supplier’s and customer’s VAT numbers? 3. Alternative exchange: Is it permissible for group members to continue exchanging these specific documents (Out of Scope) outside the Peppol network (e.g. via an internal system or by email), whilst invoicing to third parties (outside the group) takes place strictly via Peppol? I assume this will be permitted provided that the members mutually agree to send documents by other means. 4. Technical processing: Will the system accept and process invoices where both the sender and recipient have the same VAT registration number but different VAT identification numbers in the message header? During testing, when I entered invoices with the same VAT registration number, I received the following error: “Description: [BR-O-02] – An invoice containing an invoice line (BG-25) where the invoiced item’s VAT category code (BT-151) is ‘Not subject to VAT’ must not contain the seller’s VAT identifier (BT-31), the seller’s tax representative’s VAT identifier (BT-63) or the buyer’s VAT identifier (BT-48).Location: /Invoice[1]”, and if I enter it without a VAT number, the invoice fails because it is missing the VAT number.

1. As a VAT group is regarded as a single taxable person for VAT purposes, supplies of goods and services made within the group, i.e. between individual group members, are not considered taxable transactions and are therefore not subject to value added tax. For VAT purposes, these supplies between individual group members are regarded merely as ‘internal supplies’ within a single taxable person, which means that VAT does not apply to these supplies as they are not subject to tax. Supplies between members of the same group are not subject to the obligation to issue an invoice under Section 72 of the VAT Act, nor to the obligation to issue an electronic invoice under Section 85o of the VAT Act, nor to the reporting obligation under Section 85o of the VAT Act. This means that invoices issued between individual group members without the application of VAT are not subject to the provisions relating to the delivery service (the Peppol network). 2. Transactions that would be voluntarily invoiced via the Peppol network should, in accordance with the Peppol network specification, be assigned VAT category code “O”, as these are transactions not subject to tax. In this case, the rules of the BR-O group apply, including rule BR-O-02, which explicitly requires that neither the customer nor the supplier (or their tax representative) should have a VAT registration number stated. Furthermore, if VAT category “O” is applied, no other category may be stated on the invoice (as specified, for example, by rules BR-O-01 or BR-O-12). Based on these rules, if entities – members of a VAT group – decide to use the Peppol portal on a voluntary basis (see previous answer), they will not be able to state the group’s VAT registration number on the invoice, but only the unique VAT registration number of the group member. 3. Given that supplies between members of the same group are not subject to tax and, under the VAT Act, there is no obligation to issue an invoice for such supplies, the provisions of the VAT Act requiring consent to the sending of an electronic invoice by means other than a delivery service do not apply to invoices issued between individual group members. Where there is an obligation to issue an electronic invoice pursuant to Section 85o of the VAT Act to third parties (outside the group), Section 85o(2) of the VAT Act requires the consent of the recipient of the supply to send an electronic invoice by means other than a delivery service via the Peppol network. 4. The situation described is the result of applying business rule BR-O-02 (see the answer to question no. 2). The system prevented the e-invoice from being issued, as it contained the VAT category code “O”; in such cases, the VAT registration number of the supplier, customer or tax representative must not be stated on the invoice. The fact that the VAT registration numbers of the customer and the supplier are identical in CompanyID <PartyTaxScheme> was not relevant in this case. The VAT registration number in the header represents the EndPointID, which, in the Slovak context, is used to route the e-invoice from the supplier to a specific customer. The CompanyID in PartyTaxScheme is the VAT registration number of the customer/supplier. In Peppol BIS 3.0, there is no defined rule that compares the EndPointID with the CompanyID; in other words, the VAT registration number used as the rooting attribute for the supplier/customer is not checked against their VAT registration number (CompanyID). Entering the correct VAT number in the endPointID ensures that the invoice is sent to the correct recipient. From a purely technical perspective, if the VAT category code “O” were not used, but, for example, “S”, the invoice should still pass validation. Prepared by: Financial Directorate of the Slovak Republic July 2026

Primary source: Financial Administration of the Slovak Republic, FAQ 9/VAT/2025/IM k e-invoice, July 2026 update. Processed and checked on 13 July 2026.