# CII-FREXT-SR-439

Source: https://xmlvalid.com/rules/CII-FREXT-SR-439

> ChargeAmount should exist maximum once

- Level: error
- Rule sets: EXTENDED-CTC-FR rules (CII) 1.4.0.04
- Context: `/rsm:CrossIndustryInvoice/rsm:SupplyChainTradeTransaction/ram:IncludedSupplyChainTradeLineItem/ram:SpecifiedLineTradeAgreement`
- Test: `count(ram:NetPriceProductTradePrice/ram:ChargeAmount) le 1`

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