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 Instead of ignoring this data and leaving it unpublished, OCDS encourages publishers to collaborate on the creation of extensions to the standard.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 might provide features needed by only a small number of publishers or users, or might be used to document a publisher's additional fields or codelist values.

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

Using existing extensions

Extensions are applied by adding their URLs to the extensions array in the release package or record package. You can discover extensions, read their documentation and find the URL to add using the Extension Explorer.

This version of OCDS uses these specific versions of core extensions:

Developing new extensions

If you have additional fields which cannot be mapped to the OCDS schema or an existing extension, you ought to include these in your OCDS data and create a new extension to document their structure and meaning.

Extension template

You can find the extension template on GitHub. It contains guidance on creating an extension.


Groups of extensions can be combined into profiles. OCDS provides a common core for describing contracting processes, which profiles expand to suit the disclosure requirements and user needs of a particular sector or legal framework.

OCDS for Public-Private Partnerships

OCDS for Public-Private Partnerships (PPPs) describes how to use OCDS to publish information about PPPs. The profile extends OCDS to offer a data format that follows the World Bank Group’s Framework for Disclosure in Public-Private Partnership Projects.

OCDS for the European Union

OCDS for the European Union describes how to express, in OCDS, the information in Tenders Electronic Daily (TED) notices as obliged by law within the EU.

OCDS for the Agreement on Government Procurement

OCDS for the Agreement on Government Procurement (GPA) describes how to use OCDS to publish information as obliged by the World Trade Organization’s Agreement on Government Procurement.

Linked standards

OCDS data often refers to other datasets, like company registers, government budgets and infrastructure projects. These datasets contain information that is managed outside the lifecycle of a contracting process.

Open Contracting for Infrastructure Data Standards

The Open Contracting for Infrastructure Data Standards (OC4IDS) describe what information to disclose and how to disclose it, at each stage of an infrastructure project. It connects previously siloed information to better publish and track infrastructure investment and delivery, providing data at the project level, at the contracting summary level, and at contract process detail level.

A joint effort by the Infrastructure Transparency Initiative (CoST) and the Open Contracting Partnership, it builds on best practice in open data and openness of public infrastructure procurement globally.

Open Fiscal Data Package

The Open Fiscal Data Package (OFDP) describes government budget and spending data. The Budget and spending classification extension describes how to connect OCDS and OFDP datasets.