# BT-132 Referenced purchase order line identifier

An identifier for a referenced line within a purchase order.

> BT-132 (Referenced purchase order line identifier) points a single invoice line back to the specific purchase order line it fulfils, carried in cac:OrderLineReference/cbc:LineID within BG-25. Optional under EN 16931, but valuable for automated line-level order matching in accounts payable. Example: 5.
>
> BT-132 · EN 16931 / XRechnung 3.x

## BT Reference Card

Canonical EN 16931 / XRechnung facts for this business term — citable from this anchor.

- **BT code**: BT-132
- **Name**: Referenced purchase order line identifier
- **Cardinality**: Optional (O)
- **Business group**: BG-25 INVOICE LINE
- **Data type**: Identifier
- **Example value**: 5

## Quick answer

An identifier for a referenced line within a purchase order.

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

- validate
- convert

## In plain language

An identifier for a referenced line within a purchase order.

An identifier for a referenced line within a purchase order.

Links the invoice line to the specific line in the purchase order.

## What you usually enter here

Alphanumeric identifier

Typical valid values include: 1, 5, 10, PO-LINE-001

Optional but recommended for automated matching and reconciliation.

## What goes wrong often

Avoid values like: , line

## Examples in context

Links the invoice line to the specific line in the purchase order.

Optional but recommended for automated matching and reconciliation.

## Valid Examples

- 1
- 5
- 10
- PO-LINE-001

## Invalid Examples

- line

## Related Fields

Links the invoice line to the specific line in the purchase order.

- [BT-126 Invoice line identifier](/resources/xrechnung/bt-126-invoice-line-identifier)
- [BT-13 Purchase Order Reference](/resources/xrechnung/bt-13-purchase-order-reference)

## 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-132

### Data Type:
identifier

### Cardinality:
0..1

### Requirement:
Optional

### Max Length:
50 characters

### Since Version:
Optional

## XML Implementation

### UBL 2.1 Syntax
```
/Invoice/cac:InvoiceLine/cac:OrderLineReference/cbc:LineID
```

### CII (UN/CEFACT) Syntax
```
/CrossIndustryInvoice/SupplyChainTradeTransaction/ApplicableHeaderTradeSettlement/ram:SpecifiedTradeSettlementLineMonetarySummation/ram:ReferencedDocumentLineDocument/ram:LineID
```

## Why the standard cares about this field

### Business Context
Links the invoice line to the specific line in the purchase order.

### Legal Requirement
Optional but recommended for automated matching and reconciliation.

## FAQ

### When should I provide the Referenced purchase order line identifier (BT-132)?
Provide BT-132 when the buyer requires line-level PO matching, so each invoice line points back to a specific purchase order line. It is meaningful only when the order reference BT-13 is present at document level; without BT-13 there is no order for the line to reference.

### What format does BT-132 use and how does it relate to BT-13?
BT-132 is a free-text line identifier (the order line number) matching how the buyer numbered lines on the purchase order referenced by BT-13. There is no fixed pattern in EN 16931, but the value must correspond to a real line in that order so the buyer can reconcile it.

## 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)