# BR-DEC-23 Invoice line net amount must not exceed two decimal places

The BT-131 Invoice line net amount is limited to a maximum of two decimal places. Any value carrying three or more fractional digits fails EN16931 validation.

## Problem Description

> **ERROR**: EN 16931 decimal precision rule (BR-DEC)

## Context and Significance

This is an EN16931 core decimal-precision constraint enforced by KoSIT: every monetary amount in the invoice must be expressed with no more than two decimals.

## Solution

Round BT-131 to two decimal places before serialising the amount, and apply the same rounding used in the BR-CO total and sum calculations so the invoice still reconciles.

- [Validate XML](/en/xrechnung-validator?source=resource&rule=BR-DEC-23)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&rule=BR-DEC-23)

## Valid Examples

- BT-131 = 100.00 — two decimals accepted

## Invalid Examples

- BT-131 = 100.000 — three decimals rejected

## Code Examples

### Valid XML
```
<cac:InvoiceLine>
  <cbc:ID>1</cbc:ID>
  <cbc:LineExtensionAmount currencyID="EUR">100.00</cbc:LineExtensionAmount>
</cac:InvoiceLine>
```

### Invalid XML
```
<cac:InvoiceLine>
  <cbc:ID>1</cbc:ID>
  <cbc:LineExtensionAmount currencyID="EUR">100.000</cbc:LineExtensionAmount>
</cac:InvoiceLine>
```

## Affected Fields

- [BT-131 Invoice line net amount](/resources/xrechnung/bt-131-invoice-line-net-amount)

## Related Rules

- [BR-CO-10](/resources/kosit-validator-errors/br-co-10-sum-of-line-net-amounts-must-equal-line-total)

## Validation Tools

- [Official KoSIT Validator](https://github.com/itplr-kosit/validator): Run the official KoSIT validator with the XRechnung configuration to check EN 16931 and XRechnung rules.
- [Convert PDF to XRechnung](/pdf-to-xrechnung): Find validation errors during conversion and review each correction.

## Related Resources

- [Official Specification](https://docs.peppol.eu/poacc/billing/3.0/rules/ubl-tc434/)
- [Test Suite](https://github.com/itplr-kosit/xrechnung-testsuite)
- [All validation errors](/resources/kosit-validator-errors): Overview of the EN 16931, XRechnung and Peppol validation rules explained here.