KSEF-008:GTU code missing
Fix: Assign GTU codes to products that require them. Provide the required value in the free validator.
Certain goods/services require GTU (Grupy Towarów i Usług) classification codes. Required for alcohol (GTU_01), fuel (GTU_02), heating oil (GTU_03), tobacco (GTU_04), and other specific categories.
Engine Classification
Business data required · Explicit input workflow · No assumptions made
Required input: GTU Classification Code
What is KSEF-008?
KSEF-008 is a warning validation rule defined in the KSeF specification (POL national rules).
The invoice may pass transmission, but this non-compliance can cause problems during tax audits or buyer-side processing.
Why This Error Matters
KSEF-008 is a soft failure that can cause issues at the receiving end — tax audits, ERP processing, or VAT reconciliation mismatches.
Validator Behavior
- ·Generates validation warning
- ·Error returned: KSEF-008
- ·Specification: KSeF
How to Fix It
Technical Reference
Code Example
<GTU>GTU_01</GTU>Common Causes
- ·GTU requirement overlooked
- ·New product without GTU assignment
- ·GTU codes changed by regulation
Seeing this in production? The API handles KSEF-008 automatically. See the fix response →
Frequently Asked Questions
Certain goods/services require GTU (Grupy Towarów i Usług) classification codes. Required for alcohol (GTU_01), fuel (GTU_02), heating oil (GTU_03), tobacco (GTU_04), and other specific categories.
Assign GTU codes to products that require them. Invoice Navigator detects this error and prompts for the required business data before applying a safe fix.
KSEF-008 is a warning that may not always cause rejection, but it indicates a potential compliance issue that should be addressed to ensure full compatibility.
KSEF-008 requires specific business data to resolve. Invoice Navigator detects the error and guides you through providing the needed information, then applies the fix with full audit documentation.
Related Content
Last updated: 3 March 2026
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