attestwireAttestwire › Rule reference › BR-DEC-24
BR-DEC-24 A line allowance amount may have at most two decimals
noun · EN 16931 · fatal · BT-136
For a sample invoice, the library reports: The allowed maximum number of decimals for the invoice line allowance amount (BT-136) is 2, but lines[0].allowances[0].amount is 1.005, which has 3.
- Business term
BT-136- Severity
fatal
The fix
Round lines[0].allowances[0].amount to two decimals before assigning it (1.00 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
"amount": 1.00What 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:
{
"rule": "BR-DEC-24",
"field": "BT-136",
"severity": "fatal",
"message": "The allowed maximum number of decimals for the invoice line allowance amount (BT-136) is 2, but lines[0].allowances[0].amount is 1.005, 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 line allowance is subtracted from the line net amount (BT-131), and BT-131 must land on two decimals. Rounding the line total while leaving the allowance long only hides the extra digits from your own display — they still reach the XML.",
"fix": "Round lines[0].allowances[0].amount to two decimals before assigning it (1.00 here). Use half-up rounding away from zero — this package exports round2(), which handles the cases Math.round and toFixed get wrong.",
"example": "\"amount\": 1.00",
"xpath": "/ubl:Invoice/cac:InvoiceLine[1]/cac:AllowanceCharge[1]/cbc:Amount",
"docsUrl": "https://attestwire.com/rules/BR-DEC-24"
}
xpath is always a UBL path. On a CII invoice, look for the
matching CII field instead.