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PDTF PDTF2
Proposed specification for review. We are seeking feedback on key architectural choices in the industry consultation.

Property Data Trust Framework

An open standard for property data that any party to a transaction can verify for themselves, without having to trust whoever sent it.
Read the overview Open questions for consultation

What it is

Section titled “What it is”

PDTF 2.0 makes each piece of property data independently verifiable. A title register extract, an EPC, a local authority search, a verified identity: each is signed by the organisation that produced it, can be checked by anyone who receives it, and can be revoked when it stops being true.

That removes the need to trust the platform or the inbox the data arrived through. The receiving conveyancer, lender or agent checks the signature, not the sender.

The same property applies when the receiving party is software. As more of the work in a transaction is done by AI assistants acting for professionals, a signed credential is a fact an agent can rely on, where a document pulled from an API is only a claim.

PDTF 2.0 is built on W3C Verifiable Credentials for the data and OpenID Federation for deciding who is allowed to issue what. The trust model, explained without jargon.

Governance

Section titled “Governance”

The framework is designed to sit inside the UK Government’s Smart Data model. The Property Data Standards Company acts as the sector-specific implementation entity for property, operating a federation trust anchor that issues trust marks to accredited third-party providers. HM Land Registry is identified as the likely lead regulator.

Two pieces of policy frame the work. MHCLG’s Home Buying and Selling Reform Roadmap commits to a smart data scheme for property, a voluntary accreditation scheme for data standards, and secure sharing of trusted information between professionals. The CFIT Open Property coalition is building the shared trust, interoperability and digital property ID infrastructure the market needs, and mapping existing standards, PDTF among them, to a common conformance framework.

How the framework is governed

Where to start

Section titled “Where to start”

Property professionals

Agents, conveyancers, lenders and regulators who need to rely on the data in front of them.

Why property data breaks today

Technical leaders

CTOs, architects and product managers weighing PDTF for their own systems.

The architecture in ten minutes

Developers

Engineers building adapters, verifying credentials, or pulling property data into an application.

Quickstart

The entity graph

Section titled “The entity graph”

Instead of one large property data pack, PDTF 2.0 works with ten entities. Five carry data: Transaction, Property, Title, Person and Organisation. Five are thin relationship credentials that embody a party’s role: SellerCapacity, Offer, Gift, Representation and TransactionRole. Each is verifiable on its own and composes with the others.

So a title credential from HM Land Registry can be checked without the transaction it was issued for. An EPC travels with the property rather than with one sale. A change of seller can be revoked without invalidating everything else in the pack.

How the entities fit together

The specification

Section titled “The specification”

Ten documents, numbered as they are in the spec repository. Gaps in the numbering are specifications still being drafted.

  1. 00Architecture overview

    The design as a whole and how trust is expected to evolve.

  2. 01Entity graph and schema

    The ten entities, their schemas, and how they compose.

  3. 02Verifiable credentials data model

    How property data maps onto W3C Verifiable Credentials.

  4. 03DID methods and identifiers

    Identifiers for people, organisations, transactions and properties.

  5. 04OpenID Federation trust architecture

    Who may issue what, and how a verifier finds out.

  6. 06Key management

    Generating, rotating and protecting signing keys.

  7. 07State assembly

    Building the current state of a transaction from its credentials.

  8. 13Reference implementations

    Validator, graph composer and resolver behaviour.

  9. 14Credential revocation

    Status lists and how a credential is withdrawn.

  10. 15Conformance testing

    What an implementation has to pass.

Open standard, open source

Section titled “Open standard, open source”

PDTF 2.0 is developed by the Property Data Standards Company and published under an open licence. The specifications, reference implementations and tooling are on GitHub. The architecture is still proposed, not settled: the consultation lists the questions we most want challenged.