Contact person

Must e-invoice include contact persons for the supplier and customer?

Short answer

No. The supplier contact name BT-41, telephone BT-42 and email BT-43, and the customer contact fields BT-56 to BT-58, are optional under EN 16931 and Peppol BIS Billing 3.0. Act No. 222/2004 Z. z. on VAT does not list them among the mandatory invoice particulars in § 74.

BT-41▣43

Supplier contact

Name, phone, e-mail "optional.

BT-56♦58

Customer contact

The same structure on the customer's side.

Optional by EN 16931

Does not change the validity of the invoice

The absence of contact does not block validation.

Not in Section 74

Slovak law does not require it

The mandatory particulars of the invoice are missing.

Detailed explanation

Although this information is optional, filling it in is useful in practice, particularly for automated processing or when dealing with exceptions — if a received invoice fails a check or contains an discrepancy, the contact details allow the customer to quickly contact a specific person at the supplier without having to look for contact details outside the invoice. Many invoicing software programmes therefore populate these fields automatically from the company’s profile, even though this is not required by law.

As set out in the Act

The list of mandatory invoice details is set out in Section 74(1) of Act No. 222/2004 Coll. on VAT, and does not include a contact person amongst them. Fields BT-41 to BT-43 and BT-56 to BT-58 are defined by the EN 16931 standard as optional (recommended) business terms.

Practical examples

The invoicing software automatically populates the invoicing department’s email address in BT-43, although this is not required by law.
If the customer encounters a problem with a received invoice, they will use the contact details from BT-42 to avoid having to search for a telephone number on the supplier’s website.
A small sole trader does not fill in these fields in their invoicing software, and their invoices are still fully valid and compliant with the law.

Most common mistakes

“Without a contact person, the invoice will not pass Peppol validation.” The contact fields are optional; their absence does not affect validation.
“A contact person is a statutory requirement for an invoice.” Section 74 of Act No. 222/2004 Coll. on VAT does not list it among the mandatory elements.
“The customer’s contact details are only provided if the supplier also has them.” These are two separate sets of fields which are filled in independently of one another, depending on the availability of the data.

Conclusion

Supplier and customer contact details are optional under EN 16931 and Slovak VAT law, although they can make exception handling easier.

Legal basis

Act No. 222/2004 Coll. on VAT, Section 74(1) (calculation of the mandatory particulars of the invoice)
EN 16931 a Peppol BIS Billing 3.0, business terms BT-41 to BT-43 a BT-56 to BT-58