# BT-19 Buyer accounting reference

Reference the buyer uses internally to book or approve the invoice.

> BT-19 (Buyer accounting reference) is a free-text textual code the buyer needs to post the invoice to the right cost centre, project, or ledger account. Optional under EN 16931 but routinely required by ERP integrations on the buyer side. Example: Costcenter-12345.
>
> BT-19 · EN 16931 / XRechnung 3.x

## BT Reference Card

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

- **BT code**: BT-19
- **Name**: Buyer accounting reference
- **Cardinality**: Optional (O)
- **Business group**: BG-3 PRECEDING INVOICE REFERENCE
- **Data type**: Text
- **Example value**: Costcenter-12345

## Quick answer

Reference the buyer uses internally to book or approve the invoice.

> **Invoice basics**: Core document identifiers, dates, process identifiers, and high-level invoice context.

## In plain language

Reference the buyer uses internally to book or approve the invoice.

Reference the buyer uses internally to book or approve the invoice.

This field is common in public sector and large-enterprise flows where the buyer requires a cost-center or booking reference.

## What you usually enter here

Buyer booking or cost-center reference

Typical valid values include: CC-2040

Optional according to EN 16931-1, but often contractually required by the buyer.

## What goes wrong often

Avoid values like: , AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

## Examples in context

This field is common in public sector and large-enterprise flows where the buyer requires a cost-center or booking reference.

Optional according to EN 16931-1, but often contractually required by the buyer.

## Valid Examples

- CC-2040

## Invalid Examples

- AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

## Related Fields

This field is common in public sector and large-enterprise flows where the buyer requires a cost-center or booking reference.

- [BT-10 Buyer Reference](/resources/xrechnung/bt-10-buyer-reference-leitweg-id)
- [BT-133 Invoice line buyer accounting reference](/resources/xrechnung/bt-133-invoice-line-buyer-accounting-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-19

### Data Type:
text

### Cardinality:
0..1

### Requirement:
Optional

### Max Length:
50 characters

### Since Version:
Optional

## XML Implementation

### UBL 2.1 Syntax
```
/Invoice/cbc:AccountingCost
```

### CII (UN/CEFACT) Syntax
```
/CrossIndustryInvoice/SupplyChainTradeTransaction/ApplicableHeaderTradeSettlement/ram:PaymentReference
```

## Why the standard cares about this field

### Business Context
This field is common in public sector and large-enterprise flows where the buyer requires a cost-center or booking reference.

### Legal Requirement
Optional according to EN 16931-1, but often contractually required by the buyer.

## 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)