EN16931 Business Terms

Complete reference for all 30 business groups and 161 business terms in the EN16931 European e-invoicing standard, with UBL XML paths and related Peppol validation rules.

What are EN16931 business terms?

EN16931 is the European standard for the semantic data model of electronic invoices. It defines business groups (BG), logical containers like "Seller" or "VAT breakdown", and business terms (BT), individual data fields like "Invoice number" or "VAT rate". Each term has a standardised ID (e.g. BT-31 for seller VAT identifier), a description, cardinality rules, and a mapping to the UBL XML element path used in Peppol BIS Billing 3.0.

Document-level (BG-1 to BG-4)

Core invoice metadata: identifiers, dates, currency, process control, notes, and the invoicing period.

BG-1

Invoice information

1..1

Top-level mandatory fields that identify the invoice: number, issue date, type code, currency, and optional fields like due date, buyer reference, and tax point date code.

UBL path: /Invoice

Related rules: BR-01, BR-02, BR-03, BR-04, BR-05

IDNameCard.
BT-1Invoice number

A unique identifier for the invoice, assigned by the seller. Sequential numbering is required by most tax authorities.

cbc:ID

Rules: BR-02

1..1
BT-2Invoice issue date

The date on which the invoice was issued. Determines VAT reporting period and payment due date calculation.

cbc:IssueDate

Rules: BR-03

1..1
BT-3Invoice type code

A code specifying the functional type of the invoice. Common values: 380 (commercial invoice), 381 (credit note), 384 (corrected invoice), 389 (self-billed invoice).

cbc:InvoiceTypeCode

Rules: BR-04

1..1
BT-5Invoice currency code

The currency in which all invoice amounts are expressed, using ISO 4217 three-letter codes (e.g. EUR, USD, SEK, GBP).

cbc:DocumentCurrencyCode

Rules: BR-05

1..1
BT-6VAT accounting currency code

The currency used for VAT accounting and reporting when different from the invoice currency. Required in some Member States.

cbc:TaxCurrencyCode

0..1
BT-7Value added tax point date

The date when VAT becomes accountable for the seller and the buyer. If not stated, the issue date is used as the tax point date.

cbc:TaxPointDate

0..1
BT-8Value added tax point date code

A code indicating when VAT becomes accountable, referencing either the invoice date, delivery date, or payment date.

cac:InvoicePeriod/cbc:DescriptionCode

0..1
BT-9Payment due date

The date by which the buyer should pay. May be calculated from payment terms if not explicitly stated.

cbc:DueDate

0..1
BT-10Buyer reference

An identifier assigned by the buyer for internal routing purposes (e.g. cost centre, project code). Required by Peppol BIS 3.0.

cbc:BuyerReference

Rules: PEPPOL-EN16931-R003

0..1
BT-11Project reference

An identifier for the project to which the invoice relates.

cac:ProjectReference/cbc:ID

0..1
BT-12Contract reference

An identifier for the contract to which the invoice relates.

cac:ContractDocumentReference/cbc:ID

0..1
BT-13Purchase order reference

An identifier for the purchase order that triggered the invoice. Buyers use this for three-way matching.

cac:OrderReference/cbc:ID

0..1
BT-14Sales order reference

An identifier for the sales order issued by the seller, referenced in the invoice.

cac:OrderReference/cbc:SalesOrderID

0..1
BT-15Receiving advice reference

An identifier for the receiving advice issued by the buyer.

cac:ReceiptDocumentReference/cbc:ID

0..1
BT-16Despatch advice reference

An identifier for the despatch advice (delivery note) issued by the seller.

cac:DespatchDocumentReference/cbc:ID

0..1
BT-17Tender or lot reference

An identifier for the tender or lot to which the invoice relates, used in public procurement.

cac:OriginatorDocumentReference/cbc:ID

0..1
BT-18Invoiced object identifier

An identifier for the object on which the invoice is based (e.g. a subscription number, meter point, or vehicle).

cac:AdditionalDocumentReference/cbc:ID

0..1
BT-19Buyer accounting reference

A text value used by the buyer for internal accounting or bookkeeping (e.g. a cost centre or GL account code).

cbc:AccountingCost

0..1
BT-20Payment terms

A text description of the payment terms (e.g. '30 days net', '2% discount if paid within 10 days').

cac:PaymentTerms/cbc:Note

0..1
BG-2

Process control

1..1

Identifies the business process and specification to which the invoice conforms. Essential for automated routing and validation.

UBL path: /Invoice

Related rules: BR-01

IDNameCard.
BT-23Business process type

Identifies the business process context. For Peppol BIS 3.0, this is always 'urn:fdc:peppol.eu:2017:poacc:billing:01:1.0'.

cbc:ProfileID

1..1
BT-24Specification identifier

Identifies the specification that the invoice conforms to. For Peppol BIS Billing 3.0: 'urn:cen.eu:en16931:2017#compliant#urn:fdc:peppol.eu:2017:poacc:billing:3.0'.

cbc:CustomizationID

Rules: BR-01

1..1
BG-3

Preceding invoice reference

0..n

A reference to a previously issued invoice that is being corrected or credited. Required for credit notes and corrective invoices.

UBL path: cac:BillingReference/cac:InvoiceDocumentReference

Related rules: BR-55

IDNameCard.
BT-25Preceding invoice number

The identification of the invoice that was previously issued and is being corrected or credited.

cac:BillingReference/cac:InvoiceDocumentReference/cbc:ID

Rules: BR-55

1..1
BT-26Preceding invoice issue date

The issue date of the preceding invoice, helping uniquely identify it when numbers might not be unique across sellers.

cac:BillingReference/cac:InvoiceDocumentReference/cbc:IssueDate

0..1
BG-4

Invoice note

0..n

Free-text notes on the invoice. Can include general comments, regulatory text, or explanations. Multiple notes are allowed.

UBL path: cbc:Note

IDNameCard.
BT-21Invoice note subject code

A subject code qualifying the content of the note, based on UNTDID 4451.

cbc:Note (prefix before #)

0..1
BT-22Invoice note

Free-text note providing additional unstructured information about the invoice. In UBL, the subject code can be prefixed before a '#' separator.

cbc:Note

0..n

Period & references (BG-5, BG-14)

The invoicing period and document-level references for orders, contracts, and supporting documents.

BG-5

Invoice period

0..1

The period to which the invoice applies. Used for recurring invoices, subscriptions, or services delivered over a date range.

UBL path: cac:InvoicePeriod

IDNameCard.
BT-73Invoicing period start date

The start date of the invoicing period. Must be before or equal to the end date.

cac:InvoicePeriod/cbc:StartDate

Rules: BR-29, BR-CO-19

0..1
BT-74Invoicing period end date

The end date of the invoicing period. Must be after or equal to the start date.

cac:InvoicePeriod/cbc:EndDate

Rules: BR-30, BR-CO-19

0..1
BG-14

Additional supporting documents

0..n

References to additional documents that support or relate to the invoice — attachments, external documents, or object identifiers.

UBL path: cac:AdditionalDocumentReference

IDNameCard.
BT-122Supporting document reference

An identifier for the supporting document. Use '130' in the scheme to reference an invoiced object.

cac:AdditionalDocumentReference/cbc:ID

1..1
BT-123Supporting document description

A human-readable description of the supporting document.

cac:AdditionalDocumentReference/cbc:DocumentDescription

0..1
BT-124External document location

A URL where the supporting document can be accessed externally.

cac:AdditionalDocumentReference/cac:Attachment/cac:ExternalReference/cbc:URI

0..1
BT-125Attached document

An attached document embedded in the invoice as a base64-encoded binary object (e.g. a PDF scan of the original).

cac:AdditionalDocumentReference/cac:Attachment/cbc:EmbeddedDocumentBinaryObject

0..1

Trading parties (BG-7 to BG-13)

The seller, buyer, payee, seller tax representative, and their postal addresses and contact details.

BG-7

Seller

1..1

The party who sells the goods or services and issues the invoice. Includes electronic address, VAT identifier, legal name, and trading name.

UBL path: cac:AccountingSupplierParty/cac:Party

Sub-groups: BG-8, BG-9

Related rules: BR-06, BR-CO-26

IDNameCard.
BT-27Seller name

The full legal name of the seller as registered with the relevant authority.

cac:AccountingSupplierParty/cac:Party/cac:PartyLegalEntity/cbc:RegistrationName

Rules: BR-06

1..1
BT-28Seller trading name

A name by which the seller is known, other than the legal registered name (the 'doing business as' name).

cac:AccountingSupplierParty/cac:Party/cac:PartyName/cbc:Name

0..1
BT-29Seller identifier

An identifier for the seller, such as a GLN, DUNS number, or other identifier. The scheme attribute identifies the issuer.

cac:AccountingSupplierParty/cac:Party/cac:PartyIdentification/cbc:ID

0..n
BT-30Seller legal registration identifier

An identifier for the seller issued by a legal registration body (e.g. company registration number).

cac:AccountingSupplierParty/cac:Party/cac:PartyLegalEntity/cbc:CompanyID

0..1
BT-31Seller VAT identifier

The seller's VAT number, prefixed with the two-letter country code (e.g. DE123456789, BE0123456789).

cac:AccountingSupplierParty/cac:Party/cac:PartyTaxScheme[cac:TaxScheme/cbc:ID='VAT']/cbc:CompanyID

Rules: BR-CO-09

0..1
BT-32Seller tax registration identifier

The seller's local tax number, used in countries where a separate tax identifier exists alongside the VAT number.

cac:AccountingSupplierParty/cac:Party/cac:PartyTaxScheme[cac:TaxScheme/cbc:ID!='VAT']/cbc:CompanyID

0..1
BT-33Seller additional legal information

Additional legal information about the seller, such as share capital or registration details.

cac:AccountingSupplierParty/cac:Party/cac:PartyLegalEntity/cbc:CompanyLegalForm

0..1
BT-34Seller electronic address

The seller's electronic address for receiving documents (e.g. Peppol participant identifier). The scheme attribute identifies the network.

cac:AccountingSupplierParty/cac:Party/cbc:EndpointID

Rules: BR-62

1..1
BG-8

Seller postal address

1..1

The postal address of the seller. The country code is mandatory.

UBL path: cac:AccountingSupplierParty/cac:Party/cac:PostalAddress

Related rules: BR-08, BR-09

IDNameCard.
BT-35Seller address line 1

The main street address of the seller.

cac:AccountingSupplierParty/cac:Party/cac:PostalAddress/cbc:StreetName

0..1
BT-36Seller address line 2

Additional street address information of the seller.

cac:AccountingSupplierParty/cac:Party/cac:PostalAddress/cbc:AdditionalStreetName

0..1
BT-162Seller address line 3

A third line of the seller address, if needed.

cac:AccountingSupplierParty/cac:Party/cac:PostalAddress/cac:AddressLine/cbc:Line

0..1
BT-37Seller city

The city or town of the seller.

cac:AccountingSupplierParty/cac:Party/cac:PostalAddress/cbc:CityName

0..1
BT-38Seller post code

The postal code of the seller address.

cac:AccountingSupplierParty/cac:Party/cac:PostalAddress/cbc:PostalZone

0..1
BT-39Seller country subdivision

The subdivision (state, province, or region) of the seller address.

cac:AccountingSupplierParty/cac:Party/cac:PostalAddress/cbc:CountrySubentity

0..1
BT-40Seller country code

The country code of the seller address using ISO 3166-1 alpha-2 (e.g. BE, DE, NL, SE).

cac:AccountingSupplierParty/cac:Party/cac:PostalAddress/cac:Country/cbc:IdentificationCode

Rules: BR-09

1..1
BG-9

Seller contact

0..1

Contact details for the seller, including a contact person name, telephone number, and email address.

UBL path: cac:AccountingSupplierParty/cac:Party/cac:Contact

IDNameCard.
BT-41Seller contact point

The name of the contact person at the seller.

cac:AccountingSupplierParty/cac:Party/cac:Contact/cbc:Name

0..1
BT-42Seller contact telephone number

The telephone number of the seller contact.

cac:AccountingSupplierParty/cac:Party/cac:Contact/cbc:Telephone

0..1
BT-43Seller contact email address

The email address of the seller contact.

cac:AccountingSupplierParty/cac:Party/cac:Contact/cbc:ElectronicMail

0..1
BG-10

Buyer

1..1

The party who purchases the goods or services. Includes electronic address, VAT identifier, legal name, and trading name.

UBL path: cac:AccountingCustomerParty/cac:Party

Sub-groups: BG-11, BG-12

Related rules: BR-07, BR-CO-26

IDNameCard.
BT-44Buyer name

The full legal name of the buyer.

cac:AccountingCustomerParty/cac:Party/cac:PartyLegalEntity/cbc:RegistrationName

Rules: BR-07

1..1
BT-45Buyer trading name

A name by which the buyer is known, other than the legal name.

cac:AccountingCustomerParty/cac:Party/cac:PartyName/cbc:Name

0..1
BT-46Buyer identifier

An identifier for the buyer (e.g. GLN, DUNS number). The scheme attribute identifies the issuer.

cac:AccountingCustomerParty/cac:Party/cac:PartyIdentification/cbc:ID

0..1
BT-47Buyer legal registration identifier

An identifier for the buyer issued by a legal registration body (e.g. company registration number).

cac:AccountingCustomerParty/cac:Party/cac:PartyLegalEntity/cbc:CompanyID

0..1
BT-48Buyer VAT identifier

The buyer's VAT number, prefixed with the two-letter country code.

cac:AccountingCustomerParty/cac:Party/cac:PartyTaxScheme/cbc:CompanyID

0..1
BT-49Buyer electronic address

The buyer's electronic address for receiving documents (e.g. Peppol participant identifier).

cac:AccountingCustomerParty/cac:Party/cbc:EndpointID

Rules: BR-63

1..1
BG-11

Buyer postal address

1..1

The postal address of the buyer. The country code is mandatory.

UBL path: cac:AccountingCustomerParty/cac:Party/cac:PostalAddress

Related rules: BR-10, BR-11

IDNameCard.
BT-50Buyer address line 1

The main street address of the buyer.

cac:AccountingCustomerParty/cac:Party/cac:PostalAddress/cbc:StreetName

0..1
BT-51Buyer address line 2

Additional street address information of the buyer.

cac:AccountingCustomerParty/cac:Party/cac:PostalAddress/cbc:AdditionalStreetName

0..1
BT-163Buyer address line 3

A third line of the buyer address, if needed.

cac:AccountingCustomerParty/cac:Party/cac:PostalAddress/cac:AddressLine/cbc:Line

0..1
BT-52Buyer city

The city or town of the buyer.

cac:AccountingCustomerParty/cac:Party/cac:PostalAddress/cbc:CityName

0..1
BT-53Buyer post code

The postal code of the buyer address.

cac:AccountingCustomerParty/cac:Party/cac:PostalAddress/cbc:PostalZone

0..1
BT-54Buyer country subdivision

The subdivision (state, province, or region) of the buyer address.

cac:AccountingCustomerParty/cac:Party/cac:PostalAddress/cbc:CountrySubentity

0..1
BT-55Buyer country code

The country code of the buyer address using ISO 3166-1 alpha-2 (e.g. BE, DE, NL, SE).

cac:AccountingCustomerParty/cac:Party/cac:PostalAddress/cac:Country/cbc:IdentificationCode

Rules: BR-11

1..1
BG-12

Buyer contact

0..1

Contact details for the buyer, including a contact person name, telephone number, and email address.

UBL path: cac:AccountingCustomerParty/cac:Party/cac:Contact

IDNameCard.
BT-56Buyer contact point

The name of the contact person at the buyer.

cac:AccountingCustomerParty/cac:Party/cac:Contact/cbc:Name

0..1
BT-57Buyer contact telephone number

The telephone number of the buyer contact.

cac:AccountingCustomerParty/cac:Party/cac:Contact/cbc:Telephone

0..1
BT-58Buyer contact email address

The email address of the buyer contact.

cac:AccountingCustomerParty/cac:Party/cac:Contact/cbc:ElectronicMail

0..1
BG-13

Delivery information

0..1

Details about where and when goods or services were delivered, including the delivery date, location, and party name.

UBL path: cac:Delivery

IDNameCard.
BT-69Actual delivery date

The date on which delivery of the goods or services was made or completed.

cac:Delivery/cbc:ActualDeliveryDate

0..1
BT-70Deliver to location identifier

An identifier for the location where delivery took place (e.g. a GLN).

cac:Delivery/cac:DeliveryLocation/cbc:ID

0..1
BT-71Deliver to address line 1

The main street address of the delivery location.

cac:Delivery/cac:DeliveryLocation/cac:Address/cbc:StreetName

0..1
BT-72Deliver to address line 2

Additional street address information for the delivery location.

cac:Delivery/cac:DeliveryLocation/cac:Address/cbc:AdditionalStreetName

0..1
BT-165Deliver to address line 3

A third line of the delivery address.

cac:Delivery/cac:DeliveryLocation/cac:Address/cac:AddressLine/cbc:Line

0..1
BT-75Deliver to city

The city of the delivery location.

cac:Delivery/cac:DeliveryLocation/cac:Address/cbc:CityName

0..1
BT-76Deliver to post code

The postal code of the delivery location.

cac:Delivery/cac:DeliveryLocation/cac:Address/cbc:PostalZone

0..1
BT-77Deliver to country subdivision

The subdivision (state, province, region) of the delivery address.

cac:Delivery/cac:DeliveryLocation/cac:Address/cbc:CountrySubentity

0..1
BT-78Deliver to country code

The country code of the delivery address using ISO 3166-1 alpha-2.

cac:Delivery/cac:DeliveryLocation/cac:Address/cac:Country/cbc:IdentificationCode

0..1
BT-79Deliver to party name

The name of the party to whom the goods or services are delivered.

cac:Delivery/cac:DeliveryParty/cac:PartyName/cbc:Name

0..1

Payee & tax representative (BG-15, BG-16)

Optional payee (when different from the seller) and the seller's tax representative party.

BG-15

Payee

0..1

The party who receives the payment, when different from the seller. If the payee is the same as the seller, this group is omitted.

UBL path: cac:PayeeParty

IDNameCard.
BT-59Payee name

The name of the payee party.

cac:PayeeParty/cac:PartyName/cbc:Name

Rules: BR-17

1..1
BT-60Payee identifier

An identifier for the payee (e.g. GLN or DUNS number).

cac:PayeeParty/cac:PartyIdentification/cbc:ID

0..1
BT-61Payee legal registration identifier

An identifier for the payee issued by a legal registration body.

cac:PayeeParty/cac:PartyLegalEntity/cbc:CompanyID

0..1
BG-16

Seller tax representative party

0..1

The tax representative of the seller, appointed to handle VAT obligations on behalf of the seller in a specific country.

UBL path: cac:TaxRepresentativeParty

Related rules: BR-18, BR-19, BR-56

IDNameCard.
BT-62Seller tax representative name

The name of the seller's tax representative.

cac:TaxRepresentativeParty/cac:PartyName/cbc:Name

Rules: BR-18

1..1
BT-63Seller tax representative VAT identifier

The VAT identifier of the seller's tax representative.

cac:TaxRepresentativeParty/cac:PartyTaxScheme/cbc:CompanyID

Rules: BR-56

1..1
BT-64Tax representative address line 1

The main street address of the seller's tax representative.

cac:TaxRepresentativeParty/cac:PostalAddress/cbc:StreetName

0..1
BT-65Tax representative address line 2

Additional street address of the seller's tax representative.

cac:TaxRepresentativeParty/cac:PostalAddress/cbc:AdditionalStreetName

0..1
BT-164Tax representative address line 3

A third address line for the tax representative.

cac:TaxRepresentativeParty/cac:PostalAddress/cac:AddressLine/cbc:Line

0..1
BT-66Tax representative city

The city of the tax representative address.

cac:TaxRepresentativeParty/cac:PostalAddress/cbc:CityName

0..1
BT-67Tax representative post code

The postal code of the tax representative address.

cac:TaxRepresentativeParty/cac:PostalAddress/cbc:PostalZone

0..1
BT-68Tax representative country subdivision

The subdivision (state, province, region) of the tax representative address.

cac:TaxRepresentativeParty/cac:PostalAddress/cbc:CountrySubentity

0..1
BT-69-repTax representative country code

The country code of the tax representative address using ISO 3166-1 alpha-2.

cac:TaxRepresentativeParty/cac:PostalAddress/cac:Country/cbc:IdentificationCode

Rules: BR-19

1..1

Payment & totals (BG-17 to BG-22)

Payment instructions, document-level allowances and charges, VAT breakdown, and the monetary totals.

BG-17

Payment instructions

0..1

How the buyer should pay, including the payment means type code, remittance information, and payment account details.

UBL path: cac:PaymentMeans

Sub-groups: BG-18, BG-19

Related rules: BR-49, BR-61

IDNameCard.
BT-81Payment means type code

A code specifying the payment means (e.g. 30 = credit transfer, 58 = SEPA credit transfer, 49 = direct debit).

cac:PaymentMeans/cbc:PaymentMeansCode

Rules: BR-49

1..1
BT-82Payment means text

A text description of the payment means, providing additional detail for the buyer.

cac:PaymentMeans/cbc:PaymentMeansCode/@name

0..1
BT-83Remittance information

A payment reference such as a structured creditor reference or payment ID to include when making the payment.

cac:PaymentMeans/cbc:PaymentID

0..1
BG-18

Credit transfer

0..n

Payment account details for credit transfer (bank transfer) payments, including IBAN and BIC.

UBL path: cac:PaymentMeans/cac:PayeeFinancialAccount

Related rules: BR-61

IDNameCard.
BT-84Payment account identifier

The account identifier (typically IBAN) to which the payment should be made.

cac:PaymentMeans/cac:PayeeFinancialAccount/cbc:ID

Rules: BR-61

1..1
BT-85Payment account name

The name of the payment account (the bank account holder name).

cac:PaymentMeans/cac:PayeeFinancialAccount/cbc:Name

0..1
BT-86Payment service provider identifier

The BIC or national clearing code of the bank where the account is held.

cac:PaymentMeans/cac:PayeeFinancialAccount/cac:FinancialInstitutionBranch/cbc:ID

0..1
BG-19

Payment card information

0..1

Details of a payment card used for the transaction, including the masked card number.

UBL path: cac:PaymentMeans/cac:CardAccount

IDNameCard.
BT-87Payment card primary account number

The Primary Account Number (PAN) of the payment card. Only the last 4 to 6 digits should be included.

cac:PaymentMeans/cac:CardAccount/cbc:PrimaryAccountNumberID

1..1
BT-88Payment card holder name

The name of the payment card holder.

cac:PaymentMeans/cac:CardAccount/cbc:HolderName

0..1
BG-20

Document level allowances

0..n

Allowances (discounts) applied at the document level, reducing the invoice total before VAT.

UBL path: cac:AllowanceCharge[cbc:ChargeIndicator='false']

Related rules: BR-31, BR-32, BR-33

IDNameCard.
BT-92Document level allowance amount

The amount of the document-level allowance (discount), excluding VAT.

cac:AllowanceCharge/cbc:Amount

Rules: BR-31

1..1
BT-93Document level allowance base amount

The base amount from which the allowance percentage is calculated.

cac:AllowanceCharge/cbc:BaseAmount

0..1
BT-94Document level allowance percentage

The percentage used to calculate the allowance from the base amount.

cac:AllowanceCharge/cbc:MultiplierFactorNumeric

0..1
BT-95Document level allowance VAT category code

The VAT category code applicable to the allowance (e.g. S, Z, E, AE, K, G, O, L, M).

cac:AllowanceCharge/cac:TaxCategory/cbc:ID

Rules: BR-32

1..1
BT-96Document level allowance VAT rate

The VAT rate (as a percentage) applicable to the allowance.

cac:AllowanceCharge/cac:TaxCategory/cbc:Percent

0..1
BT-97Document level allowance reason

The reason for the allowance in free text.

cac:AllowanceCharge/cbc:AllowanceChargeReason

Rules: BR-33

0..1
BT-98Document level allowance reason code

A code for the reason of the allowance, from the UNTDID 5189 code list.

cac:AllowanceCharge/cbc:AllowanceChargeReasonCode

Rules: BR-33

0..1
BG-21

Document level charges

0..n

Charges (surcharges) applied at the document level, such as packing, transport, or handling fees.

UBL path: cac:AllowanceCharge[cbc:ChargeIndicator='true']

Related rules: BR-36, BR-37, BR-38

IDNameCard.
BT-99Document level charge amount

The amount of the document-level charge, excluding VAT.

cac:AllowanceCharge/cbc:Amount

Rules: BR-36

1..1
BT-100Document level charge base amount

The base amount from which the charge percentage is calculated.

cac:AllowanceCharge/cbc:BaseAmount

0..1
BT-101Document level charge percentage

The percentage used to calculate the charge from the base amount.

cac:AllowanceCharge/cbc:MultiplierFactorNumeric

0..1
BT-102Document level charge VAT category code

The VAT category code applicable to the charge.

cac:AllowanceCharge/cac:TaxCategory/cbc:ID

Rules: BR-37

1..1
BT-103Document level charge VAT rate

The VAT rate (as a percentage) applicable to the charge.

cac:AllowanceCharge/cac:TaxCategory/cbc:Percent

0..1
BT-104Document level charge reason

The reason for the charge in free text.

cac:AllowanceCharge/cbc:AllowanceChargeReason

Rules: BR-38

0..1
BT-105Document level charge reason code

A code for the reason of the charge, from the UNTDID 7161 code list.

cac:AllowanceCharge/cbc:AllowanceChargeReasonCode

Rules: BR-38

0..1
BG-22

Document totals

1..1

The monetary totals of the invoice: line extension amount, allowance/charge totals, tax amounts, and the amount due for payment.

UBL path: cac:LegalMonetaryTotal

Related rules: BR-12, BR-13, BR-14, BR-15, BR-CO-10, BR-CO-11, BR-CO-12, BR-CO-13

IDNameCard.
BT-106Sum of invoice line net amount

The sum of all invoice line net amounts. This is the total before allowances, charges, and VAT.

cac:LegalMonetaryTotal/cbc:LineExtensionAmount

Rules: BR-12, BR-CO-10

1..1
BT-107Sum of allowances on document level

The total of all document-level allowances.

cac:LegalMonetaryTotal/cbc:AllowanceTotalAmount

Rules: BR-CO-11

0..1
BT-108Sum of charges on document level

The total of all document-level charges.

cac:LegalMonetaryTotal/cbc:ChargeTotalAmount

Rules: BR-CO-12

0..1
BT-109Invoice total amount without VAT

The invoice total excluding VAT. Equal to: line extension - allowances + charges.

cac:LegalMonetaryTotal/cbc:TaxExclusiveAmount

Rules: BR-13, BR-CO-13

1..1
BT-110Invoice total VAT amount

The total VAT amount for the invoice.

cac:TaxTotal/cbc:TaxAmount

Rules: BR-CO-14

0..1
BT-111Invoice total VAT amount in accounting currency

The total VAT amount expressed in the accounting currency, when different from the invoice currency.

cac:TaxTotal/cbc:TaxAmount (with @currencyID matching BT-6)

0..1
BT-112Invoice total amount with VAT

The total amount of the invoice including VAT. This is what the buyer owes before deducting prepayments.

cac:LegalMonetaryTotal/cbc:TaxInclusiveAmount

Rules: BR-14, BR-CO-15

1..1
BT-113Paid amount

The total amount already paid (prepayments), to be subtracted from the total.

cac:LegalMonetaryTotal/cbc:PrepaidAmount

0..1
BT-114Rounding amount

The rounding amount applied to the payable amount to arrive at a convenient payment figure.

cac:LegalMonetaryTotal/cbc:PayableRoundingAmount

0..1
BT-115Amount due for payment

The final amount the buyer must pay. Equal to: total with VAT - paid amount + rounding.

cac:LegalMonetaryTotal/cbc:PayableAmount

Rules: BR-15, BR-CO-16

1..1

VAT breakdown (BG-23)

The VAT breakdown showing taxable amounts and tax amounts per VAT category and rate.

BG-23

VAT breakdown

1..n

Each entry represents a unique combination of VAT category code and VAT rate. The sum of all VAT category tax amounts must equal the invoice total VAT amount.

UBL path: cac:TaxTotal/cac:TaxSubtotal

Related rules: BR-45, BR-46, BR-47, BR-48, BR-CO-17, BR-CO-18

IDNameCard.
BT-116VAT category taxable amount

The total amount subject to this specific VAT category and rate.

cac:TaxTotal/cac:TaxSubtotal/cbc:TaxableAmount

Rules: BR-45

1..1
BT-117VAT category tax amount

The calculated VAT amount for this category. Usually: taxable amount x rate / 100.

cac:TaxTotal/cac:TaxSubtotal/cbc:TaxAmount

Rules: BR-46

1..1
BT-118VAT category code

The VAT category code for this breakdown entry: S (Standard), Z (Zero), E (Exempt), AE (Reverse charge), K (Intra-community), G (Export), O (Not subject), L (Canary Islands), M (Ceuta/Melilla).

cac:TaxTotal/cac:TaxSubtotal/cac:TaxCategory/cbc:ID

Rules: BR-47

1..1
BT-119VAT category rate

The VAT percentage rate for this category (e.g. 21, 9, 6, 0).

cac:TaxTotal/cac:TaxSubtotal/cac:TaxCategory/cbc:Percent

Rules: BR-48

0..1
BT-120VAT exemption reason text

A text explanation of why VAT is not applicable (required when VAT category is E, AE, K, G, or O).

cac:TaxTotal/cac:TaxSubtotal/cac:TaxCategory/cbc:TaxExemptionReason

0..1
BT-121VAT exemption reason code

A coded reason for the VAT exemption, using the VATEX code list from CEF (e.g. vatex-eu-ae for reverse charge).

cac:TaxTotal/cac:TaxSubtotal/cac:TaxCategory/cbc:TaxExemptionReasonCode

0..1

Invoice lines (BG-25 to BG-32)

Individual line items on the invoice, including quantity, price, allowances/charges, item details, and line-level VAT information.

BG-25

Invoice line

1..n

Each line represents a distinct product or service invoiced. An invoice must have at least one line. Contains the quantity, net amount, and references to the item, price, and VAT details.

UBL path: cac:InvoiceLine

Sub-groups: BG-26, BG-27, BG-28, BG-29, BG-30, BG-31, BG-32

Related rules: BR-16, BR-21, BR-22, BR-23, BR-24, BR-25

IDNameCard.
BT-126Invoice line identifier

A unique identifier for the invoice line within the invoice.

cac:InvoiceLine/cbc:ID

Rules: BR-21

1..1
BT-127Invoice line note

A free-text note about the invoice line.

cac:InvoiceLine/cbc:Note

0..1
BT-128Invoice line object identifier

An identifier for the object on which the line is based (e.g. a meter reading, serial number).

cac:InvoiceLine/cac:DocumentReference/cbc:ID

0..1
BT-129Invoiced quantity

The quantity of items (goods or services) invoiced on this line.

cac:InvoiceLine/cbc:InvoicedQuantity

Rules: BR-22

1..1
BT-130Invoiced quantity unit of measure code

The unit of measure for the invoiced quantity, using UN/ECE Recommendation 20 codes (e.g. C62 = unit, KGM = kilogram, HUR = hour).

cac:InvoiceLine/cbc:InvoicedQuantity/@unitCode

Rules: BR-23

1..1
BT-131Invoice line net amount

The total amount of the invoice line after allowances and charges, excluding VAT. This is the line extension amount.

cac:InvoiceLine/cbc:LineExtensionAmount

Rules: BR-24

1..1
BT-132Referenced purchase order line reference

A reference to the purchase order line that this invoice line relates to.

cac:InvoiceLine/cac:OrderLineReference/cbc:LineID

0..1
BT-133Invoice line buyer accounting reference

The buyer's accounting reference for the invoice line (e.g. a GL account or cost centre code).

cac:InvoiceLine/cbc:AccountingCost

0..1
BG-26

Invoice line period

0..1

The period to which the invoice line applies, used for recurring services or subscriptions at the line level.

UBL path: cac:InvoiceLine/cac:InvoicePeriod

IDNameCard.
BT-134Invoice line period start date

The start date of the period to which this invoice line applies.

cac:InvoiceLine/cac:InvoicePeriod/cbc:StartDate

0..1
BT-135Invoice line period end date

The end date of the period to which this invoice line applies.

cac:InvoiceLine/cac:InvoicePeriod/cbc:EndDate

0..1
BG-27

Invoice line allowances

0..n

Allowances (discounts) applied at the invoice line level, reducing the line amount.

UBL path: cac:InvoiceLine/cac:AllowanceCharge[cbc:ChargeIndicator='false']

Related rules: BR-41, BR-42

IDNameCard.
BT-136Invoice line allowance amount

The amount of the line-level allowance (discount).

cac:InvoiceLine/cac:AllowanceCharge/cbc:Amount

Rules: BR-41

1..1
BT-137Invoice line allowance base amount

The base amount from which the line allowance percentage is calculated.

cac:InvoiceLine/cac:AllowanceCharge/cbc:BaseAmount

0..1
BT-138Invoice line allowance percentage

The percentage used to calculate the line allowance from the base amount.

cac:InvoiceLine/cac:AllowanceCharge/cbc:MultiplierFactorNumeric

0..1
BT-139Invoice line allowance reason

The reason for the line-level allowance in free text.

cac:InvoiceLine/cac:AllowanceCharge/cbc:AllowanceChargeReason

Rules: BR-42

0..1
BT-140Invoice line allowance reason code

A code for the reason of the line allowance, from the UNTDID 5189 code list.

cac:InvoiceLine/cac:AllowanceCharge/cbc:AllowanceChargeReasonCode

Rules: BR-42

0..1
BG-28

Invoice line charges

0..n

Charges (surcharges) applied at the invoice line level, increasing the line amount.

UBL path: cac:InvoiceLine/cac:AllowanceCharge[cbc:ChargeIndicator='true']

Related rules: BR-43, BR-44

IDNameCard.
BT-141Invoice line charge amount

The amount of the line-level charge.

cac:InvoiceLine/cac:AllowanceCharge/cbc:Amount

Rules: BR-43

1..1
BT-142Invoice line charge base amount

The base amount from which the line charge percentage is calculated.

cac:InvoiceLine/cac:AllowanceCharge/cbc:BaseAmount

0..1
BT-143Invoice line charge percentage

The percentage used to calculate the line charge from the base amount.

cac:InvoiceLine/cac:AllowanceCharge/cbc:MultiplierFactorNumeric

0..1
BT-144Invoice line charge reason

The reason for the line-level charge in free text.

cac:InvoiceLine/cac:AllowanceCharge/cbc:AllowanceChargeReason

Rules: BR-44

0..1
BT-145Invoice line charge reason code

A code for the reason of the line charge, from the UNTDID 7161 code list.

cac:InvoiceLine/cac:AllowanceCharge/cbc:AllowanceChargeReasonCode

Rules: BR-44

0..1
BG-29

Price details

1..1

The price of the invoiced item, including the net price, base quantity, and any price discount from the gross price.

UBL path: cac:InvoiceLine/cac:Price

Related rules: BR-26, BR-27

IDNameCard.
BT-146Item net price

The net price of the item (after any price discount, before VAT). This is the price used for line amount calculation.

cac:InvoiceLine/cac:Price/cbc:PriceAmount

Rules: BR-26

1..1
BT-147Item price discount

The discount applied to the item's gross price to arrive at the net price.

cac:InvoiceLine/cac:Price/cac:AllowanceCharge/cbc:Amount

0..1
BT-148Item gross price

The gross price of the item before any price discount. Used together with item price discount to show the original price.

cac:InvoiceLine/cac:Price/cac:AllowanceCharge/cbc:BaseAmount

0..1
BT-149Item price base quantity

The quantity to which the price applies (e.g. price per 100 units). Defaults to 1 if not specified.

cac:InvoiceLine/cac:Price/cbc:BaseQuantity

0..1
BT-150Item price base quantity unit of measure code

The unit of measure for the price base quantity, using UN/ECE Recommendation 20 codes.

cac:InvoiceLine/cac:Price/cbc:BaseQuantity/@unitCode

0..1
BG-30

Line VAT information

1..1

The VAT category and rate applicable to the invoice line. Each line must reference exactly one VAT category.

UBL path: cac:InvoiceLine/cac:Item/cac:ClassifiedTaxCategory

Related rules: BR-CO-04

IDNameCard.
BT-151Invoiced item VAT category code

The VAT category code for this line item (e.g. S, Z, E, AE, K, G, O).

cac:InvoiceLine/cac:Item/cac:ClassifiedTaxCategory/cbc:ID

Rules: BR-CO-04

1..1
BT-152Invoiced item VAT rate

The VAT rate (as a percentage) for this line item.

cac:InvoiceLine/cac:Item/cac:ClassifiedTaxCategory/cbc:Percent

0..1
BG-31

Item information

1..1

Details about the invoiced item: name, description, identifiers, classification codes, country of origin, and additional attributes.

UBL path: cac:InvoiceLine/cac:Item

Sub-groups: BG-32

Related rules: BR-25

IDNameCard.
BT-153Item name

The name of the invoiced item or service.

cac:InvoiceLine/cac:Item/cbc:Name

Rules: BR-25

1..1
BT-154Item description

A free-text description of the item, providing more detail than the item name.

cac:InvoiceLine/cac:Item/cbc:Description

0..1
BT-155Item seller's identifier

An identifier for the item as assigned by the seller (e.g. a SKU or product code).

cac:InvoiceLine/cac:Item/cac:SellersItemIdentification/cbc:ID

0..1
BT-156Item buyer's identifier

An identifier for the item as assigned by the buyer (e.g. an internal product code).

cac:InvoiceLine/cac:Item/cac:BuyersItemIdentification/cbc:ID

0..1
BT-157Item standard identifier

A global identifier for the item using a standard scheme (e.g. GTIN/EAN, ISBN). The scheme ID identifies the standard.

cac:InvoiceLine/cac:Item/cac:StandardItemIdentification/cbc:ID

0..1
BT-158Item classification identifier

A classification code for the item using a standard classification scheme (e.g. CPV, UNSPSC, eCl@ss).

cac:InvoiceLine/cac:Item/cac:CommodityClassification/cbc:ItemClassificationCode

0..n
BT-159Item country of origin

The country where the item was produced or manufactured, using ISO 3166-1 alpha-2.

cac:InvoiceLine/cac:Item/cac:OriginCountry/cbc:IdentificationCode

0..1
BG-32

Item attributes

0..n

Additional properties or characteristics of the item, expressed as name-value pairs (e.g. colour, size, material).

UBL path: cac:InvoiceLine/cac:Item/cac:AdditionalItemProperty

IDNameCard.
BT-160Item attribute name

The name of the item attribute (e.g. 'Colour', 'Size', 'Weight').

cac:InvoiceLine/cac:Item/cac:AdditionalItemProperty/cbc:Name

1..1
BT-161Item attribute value

The value of the item attribute (e.g. 'Red', 'XL', '5kg').

cac:InvoiceLine/cac:Item/cac:AdditionalItemProperty/cbc:Value

1..1

Validate your invoice

Upload a UBL XML file and get instant validation against all EN16931 and Peppol BIS 3.0 rules. Errors link back to specific business terms.

Common questions

What is the difference between BG and BT in EN16931?

BG stands for Business Group — a logical container that groups related fields. BT stands for Business Term — an individual data element within a group. For example, BG-7 (Seller) is a group containing BT-27 (Seller name), BT-31 (Seller VAT identifier), and other seller-related terms. Think of BGs as folders and BTs as the files inside them.

What is BG-23 (VAT breakdown) and why is it important?

BG-23 is the VAT breakdown group. Each invoice must have at least one BG-23 entry, one for each unique combination of VAT category code (BT-118) and VAT rate (BT-119). It contains the taxable amount (BT-116) and calculated tax amount (BT-117). The sum of all BG-23 tax amounts must equal the invoice total VAT amount (BT-110). Getting this wrong is one of the most common causes of validation errors.

What fields are required in BG-25 (Invoice line)?

Every invoice line (BG-25) requires: a line identifier (BT-126), invoiced quantity (BT-129) with its unit of measure (BT-130), line net amount (BT-131), item name (BT-153), item net price (BT-146), and a VAT category code (BT-151). At least one invoice line is required per invoice. Optional fields include line notes, buyer accounting reference, order line reference, and line-level allowances or charges.

How do EN16931 business terms map to UBL XML elements?

EN16931 is syntax-neutral — it defines the semantic data model. The UBL mapping translates each business term to a specific XML element path. For example, BT-1 (Invoice number) maps to cbc:ID, BT-27 (Seller name) maps to cac:AccountingSupplierParty/cac:Party/cac:PartyLegalEntity/cbc:RegistrationName. The mapping follows the Peppol BIS Billing 3.0 syntax binding, which is the most widely used UBL implementation of EN16931.

What does cardinality mean for business terms?

Cardinality defines how many times a field can or must appear. '1..1' means exactly once (mandatory), '0..1' means zero or one time (optional), '1..n' means at least once but can repeat, and '0..n' means optional and can repeat. For example, BT-1 (Invoice number) is 1..1 (every invoice needs exactly one), while BT-22 (Invoice note) is 0..n (optional and you can have multiple notes).

What are the EN16931 VAT category codes?

EN16931 defines these VAT category codes (BT-118): S = Standard rate, Z = Zero rated, E = Exempt from tax, AE = VAT Reverse charge, K = Intra-community supply, G = Free export (outside EU), O = Outside scope of VAT, L = Canary Islands IGIC, M = Tax for Ceuta and Melilla (IPSI). Each code has specific rules — for example, category S requires a non-zero rate, while E and O require a zero tax amount.

What is the difference between EN16931 and Peppol BIS Billing 3.0?

EN16931 is the European standard defining the semantic data model for electronic invoices — the business terms and their relationships. Peppol BIS Billing 3.0 is a specific implementation profile that adds Peppol network requirements on top of EN16931, such as mandatory buyer reference (BT-10), specific identifier schemes, and additional validation rules (the PEPPOL-EN16931-* rules). An invoice can be EN16931-compliant but still fail Peppol validation if it doesn't meet the additional Peppol requirements.