# BT-144 Item classification identifier scheme identifier

The identifier for the scheme under which the item is classified.

## Quick answer

The identifier for the scheme under which the item is classified.

> **Line items**: The goods or services on each invoice line, including quantities, prices, and VAT.

## In plain language

The identifier for the scheme under which the item is classified.

The identifier for the scheme under which the item is classified.

Specifies which classification scheme is being used.

## What you usually enter here

Scheme identifier code

Typical valid values include: HS, CPV, UNSPSC, NCM

Optional according to EN 16931-1.

## What goes wrong often

Avoid values like: , AAAAAAAAAAAAAAAAAAAAA

Relevant rule codes: BR-2

## Examples in context

Specifies which classification scheme is being used.

Optional according to EN 16931-1.

## Valid Examples

- HS
- CPV
- UNSPSC
- NCM

## Invalid Examples

- AAAAAAAAAAAAAAAAAAAAA

## Related Fields

Specifies which classification scheme is being used.

- [BT-143 Item classification identifier](/resources/xrechnung/bt-143-item-classification-identifier)

## XML mapping and field facts

Open the technical reference if you need XML paths, validator rule codes, legal wording, or schema-specific mapping details.

### Field ID:
BT-144

### Data Type:
identifier

### Cardinality:
0..1

### Requirement:
Optional

### Max Length:
20 characters

### Since Version:
Optional

## XML Implementation

### UBL 2.1 Syntax
```
/Invoice/cac:InvoiceLine/cac:Item/cac:CommodityClassification/cbc:ItemClassificationCode/@listID
```

### CII (UN/CEFACT) Syntax
```
/CrossIndustryInvoice/SupplyChainTradeTransaction/ApplicableHeaderTradeSettlement/ram:SpecifiedTradeSettlementLineMonetarySummation/ram:SpecifiedTradeProduct/ram:DesignatedProductClassification/ram:ClassCode/@listID
```

## Validation Rules

### BR-2
BR-2

## Why the standard cares about this field

### Business Context
Specifies which classification scheme is being used.

### Legal Requirement
Optional according to EN 16931-1.

## Official sources and tools

- [KoSIT Validator](https://erechnungsvalidator.service-bw.de/)
- [Invoice Converter](/pdf-to-xrechnung)
- [XRechnung Standard](https://xeinkauf.de/xrechnung/)
- [Test Suite](https://github.com/itplr-kosit/xrechnung-testsuite)