BR-DEC-24 — E-Invoice Validation Rule & Fix

Fixture ID: lineAllowanceOverPrecise · XPath: /ubl:Invoice/cac:InvoiceLine[1]/cac:AllowanceCharge[1]/cbc:Amount

1. Why This Rule Triggers (Diagnostic 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.

2. How to Fix BR-DEC-24

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.

3. Valid Code / Payload Example

"amount": 1.00