# BR-RO-010

Source: https://xmlvalid.com/rules/BR-RO-010

> Numarul facturii (BT-1) trebuie sa includa cel putin un caracter numeric (0—9). #Invoice number (BT-1) must include at least one numeric character (0-9).

- Level: error
- Rule sets: Romanian RO e-Factura rules (UBL) 1.0.9
- Context: `/ubl:Invoice | /cn:CreditNote`
- Test: `matches(normalize-space(cbc:ID), '([0-9])')`

## Why it fails

- `cbc:ID` has letters only, such as a series without its number.

## How to fix it

- Make the invoice number include at least one digit, for example `FCT0001`.

Validate a document against these rules: https://xmlvalid.com/validate