# BR-Z-05 Zero-rated line rate must be zero

In an invoice line (BG-25) where the invoiced item VAT category code (BT-151) is "Zero rated", the invoiced item VAT rate (BT-152) shall be 0 (zero).

## Problem Description

> **ERROR**: EN 16931 VAT category rule

## Context and Significance

This EN16931 rule ensures category Z lines carry a 0 % rate, because category Z denotes a taxable supply at a rate of zero. In practice, the error occurs when a standard-rated line receives code Z by mistake, so check the category before you change the rate.

## Solution

Set the invoiced item VAT rate (BT-152) to 0 for category Z lines; use category S with a positive rate if VAT actually applies.

- [Validate XML](/en/xrechnung-validator?source=resource&rule=BR-Z-05)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&rule=BR-Z-05)

## Valid Examples

- Invoice line with BT-151 = Z and BT-152 = 0

## Invalid Examples

- Invoice line with BT-151 = Z but BT-152 = 19

## Code Examples

### Valid XML
```
<cac:InvoiceLine>
  <cac:Item>
    <cac:ClassifiedTaxCategory><cbc:ID>Z</cbc:ID><cbc:Percent>0</cbc:Percent><cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme></cac:ClassifiedTaxCategory>
  </cac:Item>
</cac:InvoiceLine>
```

### Invalid XML
```
<cac:InvoiceLine>
  <cac:Item>
    <cac:ClassifiedTaxCategory><cbc:ID>Z</cbc:ID><cbc:Percent>19</cbc:Percent><cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme></cac:ClassifiedTaxCategory>
  </cac:Item>
</cac:InvoiceLine>
```

## Affected Fields

- [BT-151 Invoiced item VAT category code](/resources/xrechnung/bt-151-invoice-line-vat-category-code)
- [BT-152 Invoiced item VAT rate](/resources/xrechnung/bt-152-invoice-line-vat-category-rate)

## Related Rules

- [BR-Z-01](/resources/kosit-validator-errors/br-z-01-zero-rated-vat-breakdown-required)
- [BR-Z-06](/resources/kosit-validator-errors/br-z-06-zero-rated-allowance-rate-zero)
- [BR-Z-07](/resources/kosit-validator-errors/br-z-07-zero-rated-charge-rate-zero)

## 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.