Official rule text
[PEPPOL-EN16931-R055] Invoice total VAT amount and Invoice total VAT amount in accounting currency MUST have the same operational sign
Why this error occurs
The validator evaluates the XPath test above against the context element; the assertion is false for your file.
How to fix it
Compare your file with the rule text and the test expression, adjust the element named in the context, and validate again.
What the validator checks
Checked element (context):
UBL
ubl-creditnote:CreditNote | ubl-invoice:InvoiceTest (XPath):
not(cbc:TaxCurrencyCode) or (cac:TaxTotal/cbc:TaxAmount[@currencyID=normalize-space(../../cbc:TaxCurrencyCode)] <= 0 and cac:TaxTotal/cbc:TaxAmount[@currencyID=normalize-space(../../cbc:DocumentCurrencyCode)] <= 0) or (cac:TaxTotal/cbc:TaxAmount[@currencyID=normalize-space(../../cbc:TaxCurrencyCode)] >= 0 and cac:TaxTotal/cbc:TaxAmount[@currencyID=normalize-space(../../cbc:DocumentCurrencyCode)] >= 0)CII
ram:ApplicableHeaderTradeSettlementTest (XPath):
not(/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:ApplicableHeaderTradeSettlement/ram:TaxCurrencyCode) or (ram:SpecifiedTradeSettlementHeaderMonetarySummation/ram:TaxTotalAmount[@currencyID = $taxCurrencyCode] < 0 and ram:SpecifiedTradeSettlementHeaderMonetarySummation/ram:TaxTotalAmount[@currencyID = $documentCurrencyCode] < 0) or (ram:SpecifiedTradeSettlementHeaderMonetarySummation/ram:TaxTotalAmount[@currencyID = $taxCurrencyCode] >= 0 and ram:SpecifiedTradeSettlementHeaderMonetarySummation/ram:TaxTotalAmount[@currencyID = $documentCurrencyCode] >= 0)
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
PEPPOL-EN16931-R001Business process identifier (BT-23) is missingPEPPOL-EN16931-R002No more than one note is allowed on document level, unless both the buyer and seller…PEPPOL-EN16931-R003Neither buyer reference nor purchase order reference givenPEPPOL-EN16931-R004Specification identifier is not the Peppol BIS Billing 3.0 identifierPEPPOL-EN16931-R005VAT accounting currency equals the invoice currencyPEPPOL-EN16931-R006Only one invoiced object is allowed on document levelPEPPOL-EN16931-R007Business process identifier has the wrong formatPEPPOL-EN16931-R008Document contains empty elements
Frequently asked questions
What does PEPPOL-EN16931-R055 mean?
PEPPOL-EN16931-R055 is a peppol bis billing 3.0 rule: Invoice total VAT amount and Invoice total VAT amount in accounting currency MUST have the same operational sign
Will my invoice be rejected because of PEPPOL-EN16931-R055?
Yes. PEPPOL-EN16931-R055 is flagged "fatal"; validators (KoSIT, Peppol access points, the German ZRE/OZG-RE portals) reject the invoice until it is fixed.
Which formats does PEPPOL-EN16931-R055 apply to?
Invoices and credit notes sent over the Peppol network (UBL) and, because XRechnung embeds the Peppol rule set, every XRechnung as well. Syntax: UBL and CII.
Source: Peppol BIS Billing 3.0.20 (November 2025). Catalogue generated from the official schematron on 2026-10-14.