Adds fields to the tender object to describe the legal basis of the contracting process – that is, the laws and regulations that govern the contracting process and that grant legal authority to the procuring entity.

The tender.legalBasis field is a Classification object. Example classification schemes are LEX, CELEX and ELI.

To identify the procedure used, whether by formal name or by legal citation, use the tender.procurementMethodDetails field.

To indicate whether the contracting process is covered by a treaty, like the Agreement on Government Procurement (GPA), use the coveredBy extension. To indicate whether the contracting process is accelerated, involves framework agreements, or has other modalities, browse the extensions.


If the legal basis is country-specific, it is recommended to prefix the ISO 3166-1 alpha-2 code to the classification scheme: for example, "HN-ONCAE" for the Oficina Normativa de Contratación y Adquisiciones del Estado (ONCAE) in Honduras.

In the European Union, this extension's fields correspond to eForms BT-01 (Procedure Legal Basis), BT-09 (Cross Border Law) and Article 39, paragraph 5 of Directive 2014/24/EU. For correspondences to eForms fields, see OCDS for eForms. For correspondences to Tenders Electronic Daily (TED), see OCDS for the European Union.


  "tender": {
    "crossBorderLaw": "Italian procurement legislation",
    "legalBasis": {
      "id": "32014L0025",
      "scheme": "CELEX"


Report issues for this extension in the ocds-extensions repository, putting the extension's name in the issue's title.



  • Add 'ELI' to +itemClassificationScheme.csv.


  • Add guidance on the choice of the classification scheme for country-specific legal basis.


  • Add minProperties, minItems and/or minLength properties.

This extension was originally discussed as part of the OCDS for EU profile and in pull requests.