ADNOTACJE_P18_MISSING: P_18 is mandatory in Adnotacje (§9.6)

StandardKSeF FA(3), Polish national e-invoicing systemSeverityError: the invoice is rejectedSyntaxFA(3) XMLApplies toStructured invoices (FA(3) schema) submitted to the Polish KSeF. XSD codes come from the schema, semantic codes from the Ministry of Finance information sheet; KSeF rejects invoices that fail an error-level rule.

Official rule text

[ADNOTACJE_P18_MISSING] P_18 is mandatory in Adnotacje (§9.6)

Why this error occurs

KSeF checks the FA(3) XML in two stages: XSD schema (structure, element order, data types, patterns such as NIP or dates) and semantic rules from the Ministry of Finance information sheet (consistency of amounts, annotations P_16 to P_23, roles of Podmiot2/Podmiot3, bank account formats, currency rates).

How to fix it

Fix the element named in the message. For XSD errors compare the element order and value pattern with the FA(3) schema; for semantic errors apply the cause and fix hints listed on this page. Re-validate before submitting to KSeF: a rejected invoice has no KSeF number and is not issued.

What the validator checks

Check levelsemantic / required_field

Typical causes

Missing P_18 element in Adnotacje

Add P_18 with value 2 (not reverse charge)

Check your invoice

Drop your XML or PDF on the validator and every failed rule is linked to its page here. Free, no account, the file is not stored.

Check your invoice →

Same check via API:

curl -F file=@invoice.xml https://einvoicechecker.com/v1/validate

Related rules

ADNOTACJE_NST_MISSING NoweSrodkiTransportu element is mandatory in Adnotacje (§9.6)
ADNOTACJE_P16_MISSING P_16 is mandatory in Adnotacje (§9.6)
ADNOTACJE_P17_MISSING P_17 is mandatory in Adnotacje (§9.6)
ADNOTACJE_P18A_MISSING P_18A is mandatory in Adnotacje (§9.6)
ADNOTACJE_P23_MISSING P_23 is mandatory in Adnotacje (§9.6)
ADNOTACJE_PMARZY_MISSING PMarzy element is mandatory in Adnotacje (§9.6)
ADNOTACJE_ZWOLNIENIE_MISSING Zwolnienie element is mandatory in Adnotacje (§9.6)
P15_MISSING P_15 (total amount due) is mandatory in Fa (§9.4)

Frequently asked questions

What does ADNOTACJE_P18_MISSING mean?

ADNOTACJE_P18_MISSING is a ksef fa(3) rule: P_18 is mandatory in Adnotacje (§9.6)

Will my invoice be rejected because of ADNOTACJE_P18_MISSING?

Yes. ADNOTACJE_P18_MISSING is flagged "fatal"; validators (KoSIT, Peppol access points, the German ZRE/OZG-RE portals, KSeF) reject the invoice until it is fixed.

Which formats does ADNOTACJE_P18_MISSING apply to?

Structured invoices (FA(3) schema) submitted to the Polish KSeF. XSD codes come from the schema, semantic codes from the Ministry of Finance information sheet; KSeF rejects invoices that fail an error-level rule. Syntax: FA3.

Source: KSeF FA(3) schema 1-0E + semantic rules (@ksefuj/validator 0.4). Catalogue generated from the official rule sets on 2026-10-15.