OCDS provides a common core of sections and building blocks for describing contracting processes.

Many publishers will have additional data that they could publish. Instead of ignoring this data and leaving it unpublished, OCDS encourages publishers to collaborate on the creation of extensions to the standard.

Extensions are divided into two types:

  • Core extensions are maintained as part of the standard governance process, documented as part of the standard and reviewed by the OCDS technical team with each version upgrade of OCDS. They are likely to be relevant to a large number of publishers and users.
  • Community and local extension are maintained by third-parties, or are maintained outside of the standard governance process. They may provide features required by only a small number of publishers or users, or may be used to document a publisher’s additional fields or codelist values.

All core and community extensions are listed in the extensions registry and in the documentation here. The standard technical team approves extensions for inclusion in the registry (distinguishing community from local extensions) and for inclusion in the governance process (distinguishing core from community extensions).

Using extensions

Extensions are applied by adding their URLs to the extensions array in the release or record package. To use one or more extensions, select them from the extension lists below and include the following in your release or record package metadata:


Core extensions

  Extension Description Category Extension URL
  Bid statistics and details::http://standard.open-contracting.org/1.1/en/extensions/bids/ Allowing bid statistics, and detailed bid information to be represented. bids https://raw.githubusercontent.com/open-contracting/ocds_bid_extension/v1.1.3/extension.json
  Enquiries::http://standard.open-contracting.org/1.1/en/extensions/enquiries/ The enquiries extension can be used to record questions raised during a contracting process, and the answers provided. tender https://raw.githubusercontent.com/open-contracting/ocds_enquiry_extension/v1.1.3/extension.json
  Location::http://standard.open-contracting.org/1.1/en/extensions/location/ Allow the point of delivery for a given item or the site of works to be completed to be indicated in both the tender, award and contract stage. item https://raw.githubusercontent.com/open-contracting/ocds_location_extension/v1.1.3/extension.json
  Lots::http://standard.open-contracting.org/1.1/en/extensions/lots/ A tender process may be divided into lots, where bidders can bid on one or more lots. Details of each lot can be provided here. Items, documents and other features can then reference the lot they are related to using relatedLot. Where no relatedLot identifier is given, the values should be interpreted as applicable to the whole tender. tender https://raw.githubusercontent.com/open-contracting/ocds_lots_extension/v1.1.3/extension.json
  Milestone documents::http://standard.open-contracting.org/1.1/en/extensions/milestone_documents/ Documents at the milestone level were deprecated in OCDS 1.1. This extension re-introduces the ability to attach documents to each individual milestone. milestones https://raw.githubusercontent.com/open-contracting/ocds_milestone_documents_extension/v1.1.3/extension.json
  Participation Fees::http://standard.open-contracting.org/1.1/en/extensions/participation_fee/ Where a tender process involves payment of fees to access documents, submit a proposal, or be awarded a contract, this extension can be used to provide fee details. tender https://raw.githubusercontent.com/open-contracting/ocds_participationFee_extension/v1.1.3/extension.json
  Process level title and description::http://standard.open-contracting.org/1.1/en/extensions/process_title/ For providing overall process titles and descriptions, often to give a free-text summary of the contracting process as a whole. release https://raw.githubusercontent.com/open-contracting/ocds_process_title_extension/v1.1.3/extension.json

Community extensions

  Extension Description Category Extension URL