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Documentation overview
Glossary
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XRechnung Fields
Invoice basics
BT-1
BT-2
BT-3
BT-5
BT-6
BT-7
BT-8
BT-10
BT-11
BT-12
BT-14
BT-15
BT-16
BT-17
BT-18
BT-19
BT-21
BT-22
BT-23
BT-24
BT-25
BT-26
Delivery and payment
BT-9
BT-13
BT-20
BT-59
BT-60
BT-61
BT-70
BT-71
BT-72
BT-73
BT-74
BT-75
BT-76
BT-77
BT-78
BT-79
BT-80
BT-81
BT-82
BT-83
BT-84
BT-85
BT-86
BT-87
BT-88
BT-89
BT-90
BT-91
Seller details
BT-27
BT-28
BT-29
BT-30
BT-31
BT-32
BT-33
BT-34
BT-35
BT-36
BT-37
BT-38
BT-39
BT-40
BT-41
BT-42
BT-43
BT-62
BT-63
BT-64
BT-65
BT-66
BT-67
BT-68
BT-69
Buyer details
BT-44
BT-45
BT-46
BT-47
BT-48
BT-49
BT-50
BT-51
BT-52
BT-53
BT-54
BT-55
BT-56
BT-57
BT-58
Discounts and charges
BT-92
BT-93
BT-94
BT-95
BT-96
BT-97
BT-98
BT-99
BT-100
BT-101
BT-102
BT-103
BT-104
BT-105
Taxes and totals
BT-106
BT-107
BT-108
BT-109
BT-110
BT-111
BT-112
BT-113
BT-114
BT-115
BT-116
BT-117
BT-118
BT-119
BT-120
BT-121
BT-122
BT-123
BT-124
BT-125
Line items
BT-126
BT-127
BT-128
BT-129
BT-130
BT-131
BT-132
BT-133
BT-134
BT-135
BT-136
BT-137
BT-138
BT-139
BT-140
BT-141
BT-142
BT-143
BT-144
BT-145
BT-146
BT-147
BT-148
BT-149
BT-150
BT-151
BT-152
BT-153
BT-154
BT-155
BT-156
BT-157
BT-158
BT-159
BT-160
BT-161
BT-162
BT-163
BT-164
BT-165
BT-185
BT-186
ZUGFeRD Profiles
  1. E-Invoicing Resources
  2. XRechnung Fields
  3. BT-18

Reference

Markdown export

BT-18 Invoiced object identifier

Identifier of the project, asset, case, or other business object the invoice belongs to.

Quick answerIn plain languageWhat you usually enter hereWhat goes wrong oftenExamples in contextValid ExamplesInvalid ExamplesRelated FieldsXML mapping and field factsXML ImplementationWhy the standard cares about this fieldOfficial sources and tools

Quick answer#

Identifier of the project, asset, case, or other business object the invoice belongs to.

Invoice basics

Core document identifiers, dates, process identifiers, and high-level invoice context.

In plain language#

Identifier of the project, asset, case, or other business object the invoice belongs to.

Identifier of the project, asset, case, or other business object the invoice belongs to.

Use this when invoice processing is organized around a non-order object such as a project ID, case ID, or asset number.

What you usually enter here#

Business object identifier

Typical valid values include: PROJECT-7784

Optional according to EN 16931-1.

What goes wrong often#

Avoid values like: , AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

Examples in context#

Use this when invoice processing is organized around a non-order object such as a project ID, case ID, or asset number.

Optional according to EN 16931-1.

Valid Examples#

Use these points as the practical checks for this section.

  • PROJECT-7784

Invalid Examples#

Use these points as the practical checks for this section.

  • AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

Related Fields#

Use this when invoice processing is organized around a non-order object such as a project ID, case ID, or asset number.

BT-11 Project Reference
BT-19 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-18

Data Type:

identifier

Cardinality:

0..1

Requirement:

Optional

Max Length:

50 characters

Since Version:

Optional

XML Implementation#

UBL 2.1 Syntax
/Invoice/cac:AdditionalDocumentReference[cbc:DocumentTypeCode="130"]/cbc:ID
CII (UN/CEFACT) Syntax
/CrossIndustryInvoice/SupplyChainTradeTransaction/ApplicableHeaderTradeAgreement/ram:AdditionalReferencedDocument/ram:IssuerAssignedID

Why the standard cares about this field#

Business Context

Use this when invoice processing is organized around a non-order object such as a project ID, case ID, or asset number.

Legal Requirement

Optional according to EN 16931-1.

Official sources and tools#

KoSIT Validator
Invoice Converter
XRechnung Standard
Test Suite
BT-17BT-19
On this page
Quick answerIn plain languageWhat you usually enter hereWhat goes wrong oftenExamples in contextValid ExamplesInvalid ExamplesRelated FieldsXML mapping and field factsXML ImplementationWhy the standard cares about this fieldOfficial sources and tools

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