OCDS Release

In the Open Contracting Data Standard (OCDS), a release is the atomic unit of data publication. Every time a contracting authority takes a significant action in a procurement process, it issues a new release to document that action. Releases are immutable snapshots: once published, a release is not edited. If information changes, a new release is issued instead.

What is an OCDS Release?

An OCDS release is a JSON document with a defined structure. It contains:

• A unique release identifier and a timestamp marking when the release was created.
• A contracting process identifier (OCID) that links this release to all other releases in the same procurement process.
• A release tag indicating what kind of event this release documents. Common tags include "planning," "tender," "tenderUpdate," "award," "awardUpdate," "contract," "contractUpdate," "contractAmendment," and "implementation."
• Data fields relevant to that stage, such as tender value and deadline for a tender-stage release, or awarded supplier name and contract value for an award-stage release.

Because each release is timestamped and tagged, a sequence of releases tells the full story of how a procurement unfolded over time. A reader can see when the tender was first published, whether the deadline was extended, who won, and what the final contract value was.

Releases are grouped and merged into an OCDS record, which provides the consolidated, up-to-date view of the whole process. The record is what most procurement intelligence platforms surface; the underlying releases supply the audit trail.

Why OCDS releases matter for bidders

Releases enable historical analysis that static notice archives cannot. Because every update to a procurement is a new release rather than an overwrite, you can reconstruct the full timeline: Was the deadline extended? Was the estimated value revised upward before award? Was there a contract amendment six months into delivery? These questions matter when you are building a picture of a buyer's behaviour or benchmarking contract values.

When a publisher issues releases promptly and accurately, platforms aggregating their data can alert bidders to new opportunities and award outcomes in near real time. Gaps in the release sequence (for example, a tender release followed by an award release with no intermediate "tenderAmendment" releases) may indicate data quality issues worth noting when interpreting results.

Example

A Polish national authority publishes the following release sequence for a software licensing contract:

1. A "tender" release in March, announcing the open procedure with an estimated value of EUR 200,000 and a submission deadline of April 30.
2. A "tenderUpdate" release in April, extending the deadline to May 14 and clarifying a technical specification.
3. An "award" release in June, naming the winning supplier and the awarded value of EUR 185,000.
4. A "contract" release in July, publishing the signed contract and the first milestone date.

Each release is linked by the same OCID, so the full sequence is recoverable.

Frequently Asked Questions

Can a release be corrected after it is published?

OCDS treats releases as immutable records of what was published at a point in time. If an error is discovered, the publisher issues a new corrective release rather than overwriting the original. This preserves the audit trail and allows downstream systems to detect that a correction occurred.

What is the difference between a release and a record?

A release documents one event. A record merges all releases for the same contracting process into a single, current view, showing the compiled state of each section (tender, award, contract) as of the most recent release. The record also preserves a list of the underlying releases for traceability.

How do I find OCDS releases for a specific country?

The Open Contracting Partnership maintains a registry of known publishers. TED (Tenders Electronic Daily) publishes OCDS-compatible data for EU-wide notices. Country-specific portals in member states and candidate countries (including Ukraine) may publish releases through national data portals or APIs documented by the local government.