KSEF-007
Error Guide
🇵🇱 KSEF-007: Date format invalid in Poland
ErrorMandatoryManual Fix
All dates in KSeF invoices must be in YYYY-MM-DD (ISO 8601) format. Other formats are rejected.
Quick Facts
Severity
Error (rejection)
Ruleset
KSeF
Mandate
B2B Mandatory
Fix Type
Manual
Why This Matters in Poland
Poland requires e-invoicing using KSeF XML format. Invoices with this error will be rejected. They cannot be processed for Poland compliance.
Invoice Navigator covers 134 KSeF FA(2) rules for Poland. Auto-remediates 78% of top rejection errors.
How to Fix KSEF-007
Poland E-Invoicing Requirements
Phase
Status
Scope
KSeF voluntary
Live (Jan 2022)
All VAT payers (opt-in)
B2B mandatory
Live (Feb 2026)
All Polish VAT payers
B2G
Live (Feb 2026)
Included in general KSeF mandate
Common Causes
- •Polish date format DD.MM.YYYY used
- •Incorrect separator
- •Software default format wrong
Fix KSEF-007 automatically
Upload your invoice and let Invoice Navigator auto-remediate this error.