# BT-43 Seller contact email address

Email address for the seller contact point.

## Quick answer

Email address for the seller contact point.

> **Seller details**: Who issued the invoice and how the recipient can identify that business reliably.

## In plain language

Email address for the seller contact point.

Email address for the seller contact point.

Use this when invoice-related questions should be routed to a monitored mailbox instead of a generic company address.

## What you usually enter here

Email address

Typical valid values include: billing@example.com

Optional according to EN 16931-1.

## What goes wrong often

Avoid values like: not-an-email

## Examples in context

Use this when invoice-related questions should be routed to a monitored mailbox instead of a generic company address.

Optional according to EN 16931-1.

## Valid Examples

- billing@example.com

## Invalid Examples

- not-an-email

## Related Fields

Use this when invoice-related questions should be routed to a monitored mailbox instead of a generic company address.

- [BT-41 Seller contact point](/resources/xrechnung/bt-41-seller-contact-point)
- [BT-42 Seller contact telephone number](/resources/xrechnung/bt-42-seller-contact-telephone-number)

## 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-43

### Data Type:
text

### Cardinality:
0..1

### Requirement:
Optional

### Max Length:
100 characters

### Since Version:
Optional

## XML Implementation

### UBL 2.1 Syntax
```
/Invoice/cac:AccountingSupplierParty/cac:Party/cac:Contact/cbc:ElectronicMail
```

### CII (UN/CEFACT) Syntax
```
/CrossIndustryInvoice/SupplyChainTradeTransaction/ApplicableHeaderTradeAgreement/ram:SellerTradeParty/ram:DefinedTradeContact/ram:EmailURIUniversalCommunication/ram:URIID
```

## Why the standard cares about this field

### Business Context
Use this when invoice-related questions should be routed to a monitored mailbox instead of a generic company address.

### 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)