Zugferd integration mapping guide

Overview

The ZUGFeRD/Factur‑X integration is an enterprise‑grade, EN 16931–aligned solution for producing compliant e‑invoices embedded in PDF/A‑3. It delivers a transparent, field‑by‑field mapping from Younium data to ZUGFeRD structures with BT/BG schema codes, supports Basic/Comfort/Extended profiles, and provides configurable “Zugferd custom mappings” for business overrides (for example, BuyerReference, BuyerIBAN, and IsCorrectionInvoice). Built on the proven ZUGFeRD library engine, it includes robust VAT handling (including exemption reasons), credit/correction flows with proper referencing, and secure, auditable generation designed for scale and ongoing interoperability improvements.

Field Mapping Overview

Parties (Seller → Buyer)

Younium FieldZUGFeRD FieldNotes

Legal Entity

Seller name (LegalEntity.Name)

Seller namezugferd schema code BT‑27

Legal Entity

Seller street (LegalEntity.Address.Street)

Seller postal address: Address line 1zugferd schema code BG‑5/BT‑37

Legal Entity

Seller city (LegalEntity.Address.City)

Seller postal address: Cityzugferd schema code BG‑5/BT‑36

Legal Entity

Seller postcode (LegalEntity.Address.Zip)

Seller postal address: Post codezugferd schema code BG‑5/BT‑35

Legal Entity

Seller country (LegalEntity.Address.Country)

Seller postal address: Country codezugferd schema code BG‑5/BT‑40

Invoice

Seller contact (Invoice.OurReference)

Seller contact namezugferd schema code BG‑6

Legal Entity

Seller VAT ID (LegalEntity.TaxRegistrationNumber)

Seller VAT identifierzugferd schema code BT‑31

Account

Buyer name (Account.Name)

Buyer namezugferd schema code BT‑44

Account

Buyer street (Account.InvoiceAddress.Street)

Buyer postal address: Address line 1zugferd schema code BG‑8/BT‑50

Account

Buyer city (Account.InvoiceAddress.City)

Buyer postal address: Cityzugferd schema code BG‑8/BT‑53

Account

Buyer postcode (Account.InvoiceAddress.Zip)

Buyer postal address: Post codezugferd schema code BG‑8/BT‑52

Invoice

Buyer country (Invoice.InvoiceAddress.Country)

Buyer postal address: Country codezugferd schema code BG‑8/BT‑54

Invoice

Buyer contact (Invoice.YourReference)

Buyer contact namezugferd schema code BG‑9/BT‑56

Account

Buyer VAT ID (Account.TaxRegistrationNumber)

Buyer VAT identifierzugferd schema code BT‑48

Invoice

Buyer reference (Invoice.ReferenceNumber)

OR ZUGFeRD Account custom mapping

“BuyerReference”

OR ZUGFeRD Invoice custom mapping

“BuyerReference”

Buyer reference

zugferd schema code BT‑10.

Custom mapping available: Account (“BuyerReference”) and Invoice (“BuyerReference”).

Document header and references

Younium FieldZUGFeRD FieldNotes

Invoice

Invoice number (Invoice.InvoiceNumber)

Invoice numberzugferd schema code BT‑1

Invoice

Invoice date (Invoice.InvoiceDate)

Invoice issue datezugferd schema code BT‑2

Invoice

Currency (Invoice.Currency.Code)

Invoice currency codezugferd schema code BT‑5

Invoice

Buyer order number 

(Invoice.YourOrderNumber)

Buyer order reference 
(Purchase order)
zugferd schema code BT‑13. Same order number is also used for
Seller order reference (see next row).

Invoice

Seller order number (Invoice.YourOrderNumber)

Seller order reference 
(Sales order)
zugferd schema code BT‑14. Same as Buyer order reference by 
design.

Invoice

Preceding invoice link (credit/correction context)

Preceding invoice reference/datezugferd schema code BT‑25 / BT‑26. Only populated for Credit Notes and
Corrections (based on debit/credit 
link or cancellation). A note like “Credit for invoice …” or “Cancellation of invoice …” is added.

Invoice

Note (Invoice.Notes)

Document noteFree‑text; outside core BT.

Payment information (terms, means, accounts)

Younium FieldZUGFeRD FieldNotes

Invoice

Due date (Invoice.DueDate)

Payment due datezugferd schema code BT‑9

Invoice

Payment terms text 

(“Invoice due date: {Invoice.DueDate}”)

Payment terms (description)zugferd schema code BT‑20

Invoice/Legal Entity

Creditor IBAN (Invoice.BankAccount.IBAN

OR LegalEntity.IBAN if enabled)

Payment account identifier 
(IBAN)
zugferd schema code BT‑84

Invoice/Legal Entity

Creditor BIC (Invoice.BankAccount.BIC 

OR LegalEntity.BIC if enabled)

Payment service 
provider identifier (BIC)
zugferd schema code BT‑86

Invoice

Creditor account name 

(Invoice.BankAccount.Name)

Payment account namezugferd schema code BT‑85

Account

Buyer IBAN (ZUGFeRD Account custom mapping “BuyerIBAN”)

OR settings.IbanCustomFieldMappingField

Debited account

identifier (Buyer IBAN)

zugferd schema code BT‑91. Prefer ZUGFeRD custom mapping 
“BuyerIBAN”. Note: settings.IbanCustomFieldMappingField is 
deprecated and will be removed.

Derived

Presence of Buyer IBAN

Payment means type 

code

zugferd schema code BT‑81. SEPA Credit Transfer when Buyer IBAN present; Cash otherwise.

Totals (document)

Younium FieldZUGFeRD FieldNotes

Invoice

Subtotal amount (Invoice.Subtotal.Amount)

Sum of invoice line net amountzugferd schema code BT‑106

Invoice

Subtotal amount (Invoice.Subtotal.Amount)

Tax basis amountzugferd schema code BT‑110

Invoice

VAT amount (Invoice.Tax.Amount)

Invoice total VAT amountzugferd schema code BT‑111

Invoice

Total amount (Invoice.TotalAmount.Amount)

Invoice total amount with VATzugferd schema code BT‑112

Invoice

Amount due (Invoice.TotalAmount.Amount)

Amount due for paymentzugferd schema code BT‑115

VAT breakdown (per VAT rate group)

Younium FieldZUGFeRD FieldNotes

Lines

Grouped by VAT rate

VAT category taxable amountzugferd schema code BT‑116

Lines

Grouped by VAT rate

VAT category tax amountzugferd schema code BT‑117
Line VAT situationVAT category codezugferd schema code BT‑95. VAT>0 → S; VAT=0 with EU reverse‑charge → AE; VAT=0 treated as export/out‑of‑scope → G. When AE or G 
is used, exemption reason text and code are added.
Line VAT rateVAT rate (%)zugferd schema code BT‑96
Standard texts/codes 
for AE/G
VAT exemption reason 
text/code
zugferd schema code BT‑120 / BT‑121.

Lines (per invoice line)

Younium FieldZUGFeRD FieldNotes

Invoice Line

Item name (InvoiceLine.ProductName)

Item namezugferd schema code BT‑153

Invoice Line

Description (InvoiceLine.ChargeDescription)

Item descriptionzugferd schema code BT‑154

Invoice Line

UoM (InvoiceLine.UnitOfMeasure)

Invoiced quantity unit 
of measure
zugferd schema code BT‑130. Mapped to UN/ECE (hours→HUR,
pieces→H87; default H87).

Invoice Line

Quantity (derived to match totals)

Invoiced quantityzugferd schema code BT‑129

Invoice Line

Net unit price (derived)

Price details (net unit)BG‑29

Invoice Line

Gross unit price (from amounts)

Price details (gross unit)BG‑29

Invoice Line

Net amount (NetUnitPrice × Quantity)

Invoice line net amountzugferd schema code BT‑131

Invoice Line

VAT category (from VAT logic)

Item VAT category codezugferd schema code BT‑151

Invoice Line

VAT rate

Item VAT rate (%)zugferd schema code BT‑152

Invoice Line

Service period or Invoice date

Invoicing period (line) /
Delivery date
zugferd schema code BG‑26

Corrections and credits

Younium FieldZUGFeRD FieldNotes

Invoice

Correction flag (ZUGFeRD Invoice custom mapping
“IsCorrectionInvoice”)

OR ZugferdSettings 

Invoice Correction Flag Custom Field Mapping
Invoice type: Correction

zugferd schema code BT‑3.

Preceding invoice reference/date set only for
Corrections/Credit Notes; cancellation receipt note added. Prefer ZUGFeRD custom
mapping; settings.

Invoice Correction Flag Custom Field
Mapping is deprecated.

Invoice

Credit (Invoice.InvoiceType = Credit

OR Invoice.TotalAmount.Amount < 0)

Invoice type: Credit Notezugferd schema code BT‑3. Preceding invoice reference/date set; “Credit
for invoice …” note added.

Customizable overrides (summary)

Mapping NameSourcesZUGFeRD FieldNotes
Buyer reference

Invoice

Buyer reference 
(Invoice.ReferenceNumber)

OR ZUGFeRD Account custom mapping 
“BuyerReference”

OR ZUGFeRD Invoice custom mapping 
“BuyerReference”

Buyer reference — BT‑10Account and Invoice 
mappings override defaults 
when set.
Buyer IBAN

ZUGFeRD Account custom mapping “BuyerIBAN” 

OR settings.IbanCustomFieldMappingField

Debited account 
identifier — BT‑91
Prefer ZUGFeRD custom 
mapping; settings‑based approach is 
deprecated and scheduled 
for removal.
Is correction invoice

ZUGFeRD Invoice custom mapping 
“IsCorrectionInvoice” 

OR ZugferdSettings 

Invoice Correction Flag Custom Field Mapping
Invoice type 
code — BT‑3
Prefer ZUGFeRD custom mapping; settings‑based approach is 
deprecated and scheduled 
for removal.

 

 

 

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