BR-CO – Conditions and calculations

BR-CO-17: VAT amount (BT-117) does not match taxable amount and rate

ErrorEN 16931 business rule (CEN)

The rule's own wording

[BR-CO-17]-VAT category tax amount (BT-117) = VAT category taxable amount (BT-116) x (VAT category rate (BT-119) / 100), rounded to two decimals.

Source: CEN EN 16931, version 1.3.16

Meaning of the rule

In a breakdown of your invoice the stated tax amount does not match the result of the taxable amount times the rate. The norm recalculates per VAT category: base amount times rate divided by one hundred, rounded to two decimals. One cent of difference is enough for a rejection, because the recipient books the tax amount exactly as it stands in the invoice. The error usually arises when the tax is rounded per line and then summed.

What usually goes wrong

The tax was rounded per line and added up instead of being calculated on the category's total.
Taxable amount or tax amount were not recalculated after a change.
The rate in the breakdown differs from the rate of the lines.

The fix in the XML

Calculate per breakdown the tax amount from the category's taxable amount and the rate, rounded to two decimals, and enter it in cbc:TaxAmount. Line amounts serve only as a check, not as the sum.

Before – invalid

<cac:TaxSubtotal>
  <cbc:TaxableAmount currencyID="EUR">937.40</cbc:TaxableAmount>
  <cbc:TaxAmount currencyID="EUR">178.00</cbc:TaxAmount>
  <cac:TaxCategory>
    <cbc:ID>S</cbc:ID>
    <cbc:Percent>19</cbc:Percent>
    <cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme>
  </cac:TaxCategory>
</cac:TaxSubtotal>

After – corrected

<cac:TaxSubtotal>
  <cbc:TaxableAmount currencyID="EUR">937.40</cbc:TaxableAmount>
  <cbc:TaxAmount currencyID="EUR">178.11</cbc:TaxAmount>
  <cac:TaxCategory>
    <cbc:ID>S</cbc:ID>
    <cbc:Percent>19</cbc:Percent>
    <cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme>
  </cac:TaxCategory>
</cac:TaxSubtotal>

Questions and answers

Why may I not calculate the tax per line and sum it up?

Because the norm calculates the tax per category from the sum of the base amounts. Amounts rounded per line often differ by one cent in the sum.

Which rounding is meant?

Commercial rounding to two decimals: from 0.005 upwards. Truncating or banker's rounding leads to differences and thus to BR-CO-17.

EN 16931 fields

BT-117
BT-116
BT-119
BG-23

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The rule in detail

UBL · Context (XPath): cac:TaxTotal/cac:TaxSubtotal
UBL · Schematron test: (round(cac:TaxCategory[cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']/xs:decimal(cbc:Percent)) = 0 and (round(xs:decimal(cbc:TaxAmount)) = 0)) or (round(cac:TaxCategory[cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']/xs:decimal(cbc:Percent)) != 0 and ((abs(xs:decimal(cbc:TaxAmount)) - 1 < round(abs(xs:decimal(cbc:TaxableAmount)) * (cac:TaxCategory[cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']/xs:decimal(cbc:Percent) div 100) * 10 * 10) div 100 ) and (abs(xs:decimal(cbc:TaxAmount)) + 1 > round(abs(xs:decimal(cbc:TaxableAmount)) * (cac:TaxCategory[cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']/xs:decimal(cbc:Percent) div 100) * 10 * 10) div 100 ))) or (not(exists(cac:TaxCategory[cac:TaxScheme/normalize-space(upper-case(cbc:ID))='VAT']/xs:decimal(cbc:Percent))) and (round(xs:decimal(cbc:TaxAmount)) = 0))
CII · Context (XPath): //ram:ApplicableHeaderTradeSettlement/ram:ApplicableTradeTax
CII · Schematron test: (round(.[normalize-space(upper-case(ram:TypeCode)) = 'VAT']/xs:decimal(ram:RateApplicablePercent)) = 0 and (round(xs:decimal(ram:CalculatedAmount)) = 0)) or (round(.[normalize-space(upper-case(ram:TypeCode)) = 'VAT']/xs:decimal(ram:RateApplicablePercent)) != 0 and ((abs(xs:decimal(ram:CalculatedAmount)) - 1 <= round(abs(xs:decimal(ram:BasisAmount)) * (.[normalize-space(upper-case(ram:TypeCode)) = 'VAT']/xs:decimal(ram:RateApplicablePercent) div 100) * 10 * 10) div 100 ) and (abs(xs:decimal(ram:CalculatedAmount)) + 1 >= round(abs(xs:decimal(ram:BasisAmount)) * (.[normalize-space(upper-case(ram:TypeCode)) = 'VAT']/xs:decimal(ram:RateApplicablePercent) div 100) * 10 * 10) div 100 ))) or (not(exists(.[normalize-space(upper-case(ram:TypeCode))='VAT']/xs:decimal(ram:RateApplicablePercent))) and (round(xs:decimal(ram:CalculatedAmount)) = 0))

Explanation written on 14 September 2026

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