Official rule text
[ELEMENT_NOT_ALLOWED] Element not allowed at this location
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
Typical causes
- Element in wrong parent
- Typo in element name
- Wrong element order
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.
Same check via API:
curl -F file=@invoice.xml https://einvoicechecker.com/v1/validateRelated rules
INVALID_ELEMENT_VALUEElement value does not match schema constraintsREQUIRED_ELEMENT_MISSINGRequired element missing according to schemaSCHEMA_VALIDATION_FAILEDXML does not conform to FA(3) XSD schema
Frequently asked questions
What does ELEMENT_NOT_ALLOWED mean?
ELEMENT_NOT_ALLOWED is a ksef fa(3) rule: Element not allowed at this location
Will my invoice be rejected because of ELEMENT_NOT_ALLOWED?
Yes. ELEMENT_NOT_ALLOWED 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 ELEMENT_NOT_ALLOWED 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.