DodatkowyOpis in KSeF: the whole invoice or one line?
NrWiersza, Klucz and Wartosc in Poland's FA(3): assigning additional information to a line or the whole invoice.
Without NrWiersza, information in DodatkowyOpis concerns the whole invoice. For a particular item, its line number can be specified. Klucz names the information and Wartosc contains its content.
Item name versus additional information
The goods or service name belongs in P_7 within FaWiersz. DodatkowyOpis in Fa holds additional data, including legally required information for which no separate fields are provided. It does not allow omission of the service name or other dedicated data.
Three fields and two levels
NrWiersza identifies the relevant line. Klucz names the field; Wartosc contains its value. Omitting NrWiersza makes the information invoice-wide rather than specific to a selected item.
Neutral editorial example for information without an applicable dedicated field: Klucz = “Internal project label”, Wartosc = “PROJ-A”. For an invoice-wide reference, omit NrWiersza; for item 2 only, specify its line number. This illustrates data organisation, not a duty to include a project label. Source: Ministry handbook, §2.3.
What to prepare
Identify the information's name, content and whether it concerns the entire invoice or a particular item. Also check whether your software has the appropriate dedicated field. This is an organisational recommendation.
FAQ
Must NrWiersza always be provided?
No. Without it, the information concerns the whole invoice. It can be provided for information about a particular line.
What goes in Klucz and Wartosc?
The field name goes in Klucz, and its content in Wartosc, maintaining the appropriate scope of the information.
Does DodatkowyOpis replace the service name?
No. The service or goods name belongs in P_7 within FaWiersz; additional description has a separate purpose.
Source and limits
KSeF 2.0 handbook, part II, August edition, §2.3, checked on 7 October 2026; cover legal position: 1 February 2026. This concerns Poland and does not determine VAT rates, classification or attachment procedures.