Skip to main content

A Python 3 package to parse, generate and manage the EN16931 Invoice format

Project description

Python 3 package to read, write and manage the new EN16931 Invoice format.

This European Standard establishes a semantic data model of the core elements of an electronic invoice. The semantic model includes only the essential information elements that an electronic invoice needs to ensure legal (including fiscal) compliance and to enable interoperability for cross-border, cross sector and for domestic trade.


This library allows you to:

  1. De-serialize an XML in EN16931 format to a python Invoice object.

  2. Serialize a python Invoice object to a valid XML representation.

  3. Validate an Invoice using validex.

  4. Import an Invoice to B2BRouter.


You can use pip to install this package:

$ pip install en16931


You can import an invoice from an XML file:

>>> from en16931 import Invoice
>>> invoice = Invoice.from_xml('en16931/tests/files/invoice.xml')

And use the API to access its internal values and entities:

>>> invoice.issue_date
datetime.datetime(2018, 6, 11, 0, 0)
>>> invoice.seller_party
<en16931.entity.Entity at 0x7f2b7c12b860>
>>> invoice.buyer_party
<en16931.entity.Entity at 0x7f2b7c0fd160>
>>> invoice.unique_taxes
{ Tax S: 0.21  , Tax S: 0.1  }
>>> invoice.lines
[<en16931.invoice_line.InvoiceLine at 0x7f2b7c0fd400>,
 <en16931.invoice_line.InvoiceLine at 0x7f2b7c0fd518>,
 <en16931.invoice_line.InvoiceLine at 0x7f2b7c0fd748>]
>>> invoice.tax_exclusive_amount
>>> invoice.tax_amount()
>>> invoice.tax_inclusive_amount
>>> invoice.payable_amount

If you import an XML file, all relevant quantities are not computed; we use the ones defined on the XML. You can check that the computed and imported quantities match by calling the relevant methods:

>>> assert invoice.tax_exclusive_amount == invoice.subtotal()
>>> assert invoice.tax_inclusive_amount ==
>>> assert invoice.payable_amount ==

Or you can also build, step by step, an invoice:

>>> from en16931 import Invoice, Entity, InvoiceLine
>>> invoice = Invoice(invoice_id="2018-01", currency="EUR")
>>> seller = Entity(name="Acme Inc.", tax_scheme="VAT",
...                 tax_scheme_id="ES34626691F", country="ES",
...                 party_legal_entity_id="ES34626691F",
...                 registration_name="Acme INc.", mail="",
...                 endpoint="ES76281415Y", endpoint_scheme="ES:VAT",
...                 address="easy street", postalzone="08080",
...                 city="Barcelona", province="Barcelona")
>>> buyer = Entity(name="Corp Inc.", tax_scheme="VAT",
...                tax_scheme_id="ES76281415Y", country="ES",
...                party_legal_entity_id="ES76281415Y",
...                registration_name="Corp INc.", mail="",
...                endpoint="ES76281415Y", endpoint_scheme="ES:VAT",
...                address="busy street", postalzone="08080",
...                city="Barcelona", province="Barcelona")
>>> invoice.buyer_party = buyer
>>> invoice.seller_party = seller
>>> invoice.due_date = "2018-09-11"
>>> invoice.issue_date = "2018-06-11"
>>> # lines
>>> il1 = InvoiceLine(quantity=11, unit_code="EA", price=2,
...                   item_name='test 1', currency="EUR",
...                   tax_percent=0.21, tax_category="S")
>>> il2 = InvoiceLine(quantity=2, unit_code="EA", price=25,
...                   item_name='test 2', currency="EUR",
...                   tax_percent=0.21, tax_category="S")
>>> il3 = InvoiceLine(quantity=5, unit_code="EA", price=3,
...                   item_name='test 3', currency="EUR",
...                   tax_percent=0.1, tax_category="S")
>>> invoice.add_lines_from([il1, il2, il3])

And serialize it to XML:

>>> # As a string
>>> xml = invoice.to_xml()
>>> # Or save it directly to a file


This is a proof of concept implementation and not all features defined in the EN16931 standard are implemented. But it is easy, in some cases trivial, to implement them. The main not implemented features are:

  • CreditNotes are not supported.

  • File attachments are not supported.

  • Delivery information is not supported.

  • Only global charges and discounts are supported. Line discounts and charges are not supported.

  • Other potentially useful attributes (such as InvoicePeriod, BuyerReference, OrderReference, BillingReference, ContractDocumentReference, among others) are not implemented.

If you need a particular feature implemented, see the following section for feature requests.

Bugs and Feature Requests

Please report any bugs that you find here. Or, even better, fork the repository on GitHub and create a pull request (PR). We welcome all changes, big or small.


Released under the Apache License Version 2.0 (see LICENSE.txt):

Copyright (C) 2018 Invinet Sistemes

Project details

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

en16931-0.2.tar.gz (29.0 kB view hashes)

Uploaded Source

Built Distribution

en16931-0.2-py3-none-any.whl (33.5 kB view hashes)

Uploaded Python 3

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page