AttestwireRule referenceBR-DEC-28

BR-DEC-28 A line charge base amount may have at most two decimals

noun · EN 16931 · fatal · BT-142

For a sample invoice, the library reports: The allowed maximum number of decimals for the invoice line charge base amount (BT-142) is 2, but lines[0].charges[0].baseAmount is 10.005, which has 3.

Business term
BT-142
Severity
fatal

The fix

Round lines[0].charges[0].baseAmount to two decimals before assigning it (10.01 here). Use half-up rounding away from zero — this package exports round2(), which handles the cases Math.round and toFixed get wrong.

A passing value

the shape this field expects
"baseAmount": 10.01

What the library returns

The full error returned by @attestwire/en16931. It includes the rule ID, affected field and suggested correction. Developers can use this object in their application:

TeachingError
{
  "rule": "BR-DEC-28",
  "field": "BT-142",
  "severity": "fatal",
  "message": "The allowed maximum number of decimals for the invoice line charge base amount (BT-142) is 2, but lines[0].charges[0].baseAmount is 10.005, which has 3. The constraint is on the serialised value, so it is about what reaches the XML rather than about what your variable holds — and the line is where over-precision starts, since every document total downstream of it inherits the drift. A base amount is normally lifted straight out of a subtotal your own system computed, so it carries whatever precision that computation left behind. It is also the number the percentage is applied to, so an over-precise base tends to produce an over-precise amount alongside it.",
  "fix": "Round lines[0].charges[0].baseAmount to two decimals before assigning it (10.01 here). Use half-up rounding away from zero — this package exports round2(), which handles the cases Math.round and toFixed get wrong.",
  "example": "\"baseAmount\": 10.01",
  "xpath": "/ubl:Invoice/cac:InvoiceLine[1]/cac:AllowanceCharge[2]/cbc:BaseAmount",
  "docsUrl": "https://attestwire.com/rules/BR-DEC-28"
}

xpath is always a UBL path. On a CII invoice, look for the matching CII field instead.