# BR-CO-18

> The invoice must contain at least one VAT breakdown group (BG-23). Add a cac:TaxTotal/cac:TaxSubtotal describing the VAT for each category.

Checked against Peppol BIS Billing 3.0 2026.5

Canonical: https://einvoicecheck.eu/rules/br-co-18

## Official rule text

An Invoice shall at least have one VAT breakdown group (BG-23).

## Why did my invoice fail BR-CO-18?

An invoice must contain at least one VAT breakdown group (BG-23), i.e. at least one TaxSubtotal describing a VAT category, its taxable amount, VAT amount and rate. Without it the VAT cannot be reconciled and the invoice is not valid even when VAT is zero, exempt or reverse-charge.

## Common causes

- TaxTotal present but containing no cac:TaxSubtotal element.
- Exempt, zero-rated or reverse-charge invoice built with no VAT breakdown because 'there is no VAT'.
- TaxSubtotal omitted for an out-of-scope (category O) or intra-community (category K) supply.
- Serializer dropping empty-looking TaxSubtotal blocks.

## How do I fix it?

```
Add at least one breakdown, e.g. for a reverse charge: <cac:TaxSubtotal><cbc:TaxableAmount currencyID="EUR">100.00</cbc:TaxableAmount><cbc:TaxAmount currencyID="EUR">0.00</cbc:TaxAmount><cac:TaxCategory><cbc:ID>AE</cbc:ID><cbc:Percent>0</cbc:Percent><cac:TaxScheme><cbc:ID>VAT</cbc:ID></cac:TaxScheme></cac:TaxCategory></cac:TaxSubtotal>.
```