# BT-16 Despatch advice reference

Reference to the despatch advice that announced the shipment before invoicing.

## Quick answer

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

- [Validate XML](/en/xrechnung-validator?source=resource&bt=BT-16)
- [Convert invoice](/en/pdf-to-xrechnung?source=resource&bt=BT-16)

## In plain language

Reference to the despatch advice that announced the shipment before invoicing.

Reference to the despatch advice that announced the shipment before invoicing.

This field is useful in logistics-heavy flows where the buyer checks invoice, shipment, and receipt documents together.

## What you usually enter here

Despatch or shipment reference

Typical valid values include: DES-2026-44

Optional according to EN 16931-1.

## What goes wrong often

Avoid values like: , AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

## Examples in context

This field is useful in logistics-heavy flows where the buyer checks invoice, shipment, and receipt documents together.

Optional according to EN 16931-1.

## Valid Examples

- DES-2026-44

## Invalid Examples

- AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

## Related Fields

This field is useful in logistics-heavy flows where the buyer checks invoice, shipment, and receipt documents together.

- [BT-15 Receiving advice reference](/resources/xrechnung/bt-15-receiving-advice-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-16

### Data Type:
text

### Cardinality:
0..1

### Requirement:
Optional

### Max Length:
50 characters

### Since Version:
Optional

## XML Implementation

### UBL 2.1 Syntax
```
/Invoice/cac:DespatchDocumentReference/cbc:ID
```

### CII (UN/CEFACT) Syntax
```
/CrossIndustryInvoice/SupplyChainTradeTransaction/ApplicableHeaderTradeDelivery/ram:DespatchAdviceReferencedDocument/ram:IssuerAssignedID
```

## Create an XRechnung from your PDF

The converter reads the invoice and shows the fields it found before download, so you can check and correct the values. No PDF? Fill in the XRechnung directly in the form.

- [Convert invoice](/en/pdf-to-xrechnung)
- [Fill in XRechnung in the form](/en/create-xrechnung)

Download requires an account. Subscriptions from €10/month with annual billing (excl. taxes), or €5 per conversion (excl. taxes) without a subscription.

## Why the standard cares about this field

### Business Context
This field is useful in logistics-heavy flows where the buyer checks invoice, shipment, and receipt documents together.

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

## Official sources and tools

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