Validation Engine (myDATA, XSD, Business Rules)
Catch errors before AADE does. Submit with confidence.
🧪 Three Layers of Protection
Every document you upload runs through three validation “gates”:
myDATA compliance → Checks against AADE’s rules and Greek tax law.
XSD schema validation → Ensures the XML structure is correct.
Business rules → Verifies maths, checks for duplicates, applies custom policies.
💡 Why it matters: Most rejections happen because of preventable issues (wrong VAT, missing fields, schema errors). TaxLayer catches them early so you don’t waste time resubmitting.
🇬🇷 myDATA Compliance Checks
What TaxLayer looks for:
VAT numbers → Proper ΑΦΜ format + EU VIES database cross-check.
Invoice type → Auto-assigns (1.1, 1.2, 1.3, etc.) based on context.
Tax categories → Correct VAT rates for sales vs expenses.
Cross-border rules → Detects EU vs non-EU and reverse charge.
Exemption codes → Required for zero-rated/exempt invoices.
Common pain points solved:
Missing classifications → Suggested automatically.
Wrong VAT rate for the period → Checked against historical tables.
Incomplete party info → Flagged before submission.
Multi-currency issues → Validated and normalized.
🧾 XSD Schema Validation
Think of this as a “grammar check” for XML. If it fails, AADE won’t even read the file.
What’s validated:
All required XML elements are present.
Numbers, dates, and text are in the right format.
Correct namespaces and encoding (Greek characters supported).
Schema version is current and matches AADE’s latest.
Pain point solved: No more “XSD Fail” hard errors that block submissions completely.
⚡ Best practices:
Pre-validate before production.
Use templates that already conform to the XSD.
Fix errors at the field level to save time.
📏 Business Rules & Smart Checks
On top of regulatory checks, TaxLayer enforces business logic:
Math accuracy: Line totals = qty × unit price, VAT sums = correct.
Date logic: Issue date ≤ due date, reasonable ranges.
Party validation: Issuer and recipient info must match.
Document numbering: Checks sequence gaps.
Duplicates: Finds duplicates by vendor + number + date + amount.
Advanced extras:
Fuzzy matching → spots near-duplicates.
Vendor-specific rules → tailor validations for tricky suppliers.
Custom policies → define your own tolerance levels or approval workflows.
💡 Why it matters: Prevents subtle errors (rounding, sequence gaps, accidental double-submits) that are frustrating and costly to fix later.
⚡ Real-Time Validation Workflow
Here’s how it feels in practice:
Upload your documents.
Validation runs instantly (OCR → extraction → checks).
Status updates:
✅ Valid → Good to go.
⚠️ Warning → Won’t block, but should review.
❌ Error → Needs fixing before submission.
🚫 XSD Fail → Structural issue, must be resolved.
Fix inline (or in bulk for repeated issues).
Re-validate → Loop until everything is green.
📊 Validation Analytics
TaxLayer also helps you see patterns, not just fix errors:
Error trend analysis (by client, vendor, period).
Submission success rates.
Vendor performance scoring (which suppliers cause the most trouble).
Processing speed and accuracy over time.
🛠 Troubleshooting at a Glance
Common issues:
❌ Schema mismatch → Fix XML structure.
❌ Wrong data type → Reformat numbers/dates.
❌ Missing mandatory field → Complete VAT, address, or classification.
❌ Math error → Correct line or rounding.
❌ Duplicate → Remove or mark as legitimate credit note.
Quick resolution tips:
Always fix Errors/XSD Fails first.
Group similar issues for batch fixing.
Use AI Chat for step-by-step fix suggestions.
Work with suppliers if the same errors keep coming back.
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