# HR-BR-37

Source: https://xmlvalid.com/rules/HR-BR-37

> Račun mora sadržavati oznaku operatera (HR-BT-4)

- Level: error
- Rule sets: Croatian eRačun rules (UBL) 13.03.2026
- Context: `cac:AccountingSupplierParty`
- Test: `cac:SellerContact/cbc:Name`

In English: The invoice must contain the operator's label (HR-BT-4).

## Why it fails

- `cac:AccountingSupplierParty/cac:SellerContact/cbc:Name` is missing. In the Croatian extension `cac:SellerContact` describes the operator who issued the invoice, not the seller's general contact (that stays in `cac:Party/cac:Contact`).

## How to fix it

- Add `cbc:Name` with the operator's label or name to `cac:SellerContact`, next to their OIB in `cbc:ID` (HR-BR-9).

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