The invoice type code (BT-3): 380, 381 and the rest

Key takeaways

• The invoice type code (business term BT-3 of EN 16931) states the nature of the document: ordinary invoice, credit note, prepayment or corrected invoice.
• An ordinary sales invoice uses value 380; a credit note carries code 381.
• The code is mandatory and comes from a standardised list (UNTDID 1001), of which Peppol BIS Billing 3.0 keeps a subset.
• Your software writes the right code based on the document you create: you never type it.

The invoice type code, the BT-3 field of an e-invoice

The structured e-invoice is becoming the norm for B2B. In Belgium the mandate takes effect on 1 January 2026 with the Peppol BIS Billing 3.0 format. Each invoice then carries coded fields that never appeared on a PDF, and the invoice type code is one of them: it tells the recipient's software whether it is receiving an invoice, a credit note or a prepayment.

In the European standard EN 16931 this field is identified as BT-3 and it is mandatory. This article explains where it sits, which values it takes (380, 381, 384, 386) and why you never type it yourself.

What the invoice type code is for

An e-invoice is read by software, not by a person. To process it without intervention, the software must know straight away what it is dealing with. The invoice type code answers that question in a single field: is the document a sales invoice, a correction, a prepayment, a credit note?

In EN 16931, BT-3 is a mandatory field that takes exactly one value per document. That value drives the accounting treatment. An ordinary invoice increases the amount the customer owes; a credit note reduces it. Software that confuses the two corrupts the recipient's books. The code removes the ambiguity before the amounts are even read.

The values you will meet most often

The codes come from the UNTDID 1001 list (also written UNCL 1001), maintained by UN/CEFACT. EN 16931 and Peppol BIS Billing 3.0 keep only a subset. Here are the ones that recur most in everyday invoicing.

The most common invoice codes

• 380 — Commercial invoice

  The ordinary sales invoice. It is the default value for a standard invoice.

• 384 — Corrected invoice

  Replaces an earlier invoice with a corrected version.

• 386 — Prepayment invoice

  Invoices an advance payment, before delivery or performance.

• 389 — Self-billed invoice

  Issued by the customer on the supplier's behalf (self-billing).

• 326 — Partial invoice

  Invoices part of an order or an ongoing contract.

A prepayment invoice therefore carries code 386. The full list allowed on the network is longer, but these few codes cover most of an SME's flows.

380

commercial invoice

the code of an ordinary sales invoice

27

codes for an invoice

values allowed by the Peppol BIS Billing 3.0 Invoice list

5

codes for a credit note

values allowed by the CreditNote list

Invoice and credit note: two documents, two fields

Peppol BIS Billing 3.0 covers two separate documents, and each has its own BT-3 field. The invoice uses the cbc:InvoiceTypeCode element, with 380 as the common value. The credit note is a different document (CreditNote), which carries the code in its own cbc:CreditNoteTypeCode element, with 381 as the common value.

That is why code 381 never appears in an invoice: it belongs to the credit note document. Each document has not only a different field but also its own list of allowed values.

To know when to issue a document carrying code 381, read the electronic credit note; to correct an invoice already sent, read the corrective invoice.

Invoices and credit notes with the right code, without touching the XML

YouInv generates each document to the Peppol BIS Billing 3.0 profile with the expected type code, validates it and sends it over the Peppol network.

Create an accountSee pricing

What the invoice type code changes for you

In practice you never handle this code directly. When you create an invoice, your software writes 380; when you generate a credit note, it produces a CreditNote document with code 381; a prepayment invoice gets 386. The right code follows from the document type you pick on screen.

What matters is that your tool knows these rules and applies them without fail. A wrong code, and the recipient treats a credit note as an invoice, or rejects the document at validation. When choosing or upgrading your software, check that it generates each document type with the code the profile expects.

The invoice type code is only one of the coded fields of an e-invoice: the VAT exemption codes (VATEX) follow the same standardised-list logic.

Further reading

• The EN 16931 standard: the semantic model where business term BT-3 is defined.
• The UBL 2.1 format explained: the XML syntax that carries the InvoiceTypeCode.
• Peppol BIS Billing 3.0: what the format contains: the profile that defines the two documents.

The reference list is authoritative: the Peppol BIS Billing 3.0 UNCL1001 code list, published by OpenPeppol.

What is the invoice type code?

It is business term BT-3 of the EN 16931 standard, written in the cbc:InvoiceTypeCode element in UBL 2.1. It states the nature of the document: invoice, credit note, prepayment or correction. It is mandatory and takes a value from a standardised list (UNTDID 1001).

What does code 380 mean on an invoice?

Code 380 identifies a commercial invoice, that is an ordinary sales invoice. It is the value used by default for a standard invoice in the Peppol BIS Billing 3.0 format.

Which code does a credit note carry?

A credit note carries code 381. It travels in a document separate from the invoice (CreditNote), with its own cbc:CreditNoteTypeCode element.

Which code is used for a prepayment invoice?

A prepayment invoice uses code 386. A corrected invoice uses code 384, and a self-billed invoice uses code 389.

Do I have to enter this code myself?

No. Your invoicing software writes the code matching the document you create. You choose invoice or credit note on screen, and the BT-3 field is filled automatically.