# PEPPOL-EN16931-R055

> Invoice total VAT amount and Invoice total VAT amount in accounting currency MUST have the same operational sign

Checked against Peppol BIS Billing 3.0 2026.5

Canonical: https://einvoicecheck.eu/rules/peppol-en16931-r055

## Official rule text

Invoice total VAT amount and Invoice total VAT amount in accounting currency MUST have the same operational sign

## Why did my invoice fail PEPPOL-EN16931-R055?

The Invoice total VAT amount (BT-110, in document currency) and the Invoice total VAT amount in accounting currency (BT-111) must have the same arithmetic sign, since they are two representations of the same VAT figure. A positive VAT in one currency cannot correspond to a negative VAT in the other, as this would indicate a data or conversion error.

## Common causes

- A currency-conversion routine flipped the sign when computing the accounting-currency VAT.
- One amount was taken from a corrective/credit context and the other from the original, producing opposite signs.
- Manual entry or mapping error left one of the two VAT totals negative while the other is positive.

## How do I fix it?

```
Ensure both totals share the sign, e.g. document currency <cbc:TaxAmount currencyID="EUR">100.00</cbc:TaxAmount> and accounting currency <cbc:TaxAmount currencyID="SEK">1150.00</cbc:TaxAmount> (both positive).
```