API reference · AVM
Property Valuation API
The Valtaic Property Valuation API provides automated residential property valuations across England and Wales. It supports existing properties, proposed developments, individual valuations, synchronous portfolio requests and, where available, asynchronous portfolio jobs.- Base URL
https://api.valtaic.io- Version
- v3
- Coverage
- England and Wales
- Format
- JSON over HTTPS
Live capabilitiesUse GET /v3/releases/current to discover the active release, valuation-date window, limits and available endpoints.
Start Here
| Goal | Guide |
|---|---|
| Make a first valuation | Quickstart |
| Understand the service and its results | Valuation Concepts |
| Choose an endpoint | Endpoint reference |
| Construct valid input | Request schema |
| Resolve UPRNs and stored fields | Identity and stored data |
| Interpret values and evidence | Responses and evidence |
| Value proposed properties | Development valuations |
| Process portfolios | Batch and asynchronous jobs |
| Handle failures | Errors and retries |
| Handle valuation releases | Versioning and releases |
| Build a production client | Integration guide |
| Manage credentials and limits | Authentication |
| Design reliable request handling | Limits and Safeguards |
| Plan response times and batch sizes | Latency and Throughput |
Choose an Endpoint
The API supports four principal workflows:
- Individual valuations of existing properties.
- Synchronous batch valuations for portfolios.
- Development valuations for proposed properties without a registered identity.
- Durable asynchronous jobs for larger workloads that must continue if the client disconnects.
Two response formats are available:
| Depth | Intended use | Endpoint |
|---|---|---|
| Simple | Value, interval, confidence and input audit | /v3/simple-value |
| Standard | Value plus selected comparables or context | /v3/value |
Endpoint Map
| Method | Path | Purpose | Rows |
|---|---|---|---|
POST | /v3/simple-value | Lightweight existing-property valuation | 1 |
POST | /v3/value | Standard existing-property valuation | 1 |
POST | /v3/simple-batch-value | Lightweight synchronous portfolio | 2,500 |
POST | /v3/batch-value | Standard synchronous portfolio | 2,500 |
POST | /v3/development-value | Proposed-property valuation | 1 |
POST | /v3/development-batch-value | Proposed-unit schedule | 2,500 |
POST | /v3/valuation-jobs | Durable simple, standard or development portfolio | 2,500* |
GET | /v3/valuation-jobs/{job_id} | Capability-gated job status | N/A |
GET | /v3/valuation-jobs/{job_id}/results | Capability-gated completed job results | N/A |
GET | /v3/releases/current | Active release and capabilities | N/A |
GET | /v3/coverage | Non-valuing coverage check | N/A |
* The service supports up to 2,500 rows per job. Always check
limits.asynchronous_job_rows in release metadata; your plan or the request-body
limit may impose a lower limit.
Simple, standard and development batches share the published synchronous row limit. Standard and development responses can include comparables and context.
Asynchronous jobs are available only when /v3/valuation-jobs appears in the
endpoints returned by GET /v3/releases/current and the customer's plan allows
them. If it is absent, use a synchronous batch within the published limit.
Contract Behaviour
- Unknown request fields are rejected rather than silently ignored.
- Valuation response envelopes identify the
release_idused; batch rows share the identifier on their envelope. - Every valuation result includes its own status; batch clients must inspect each row.
- Valid explicit customer values take precedence over stored subject-property data, subject to the endpoint's documented conditional rules.
- Stored data is controlled by
options.use_stored_dataand disclosed ininput_resolution. - Where a UPRN is omitted, the address must resolve to one exact, unambiguous property record.
- A request that fails automated-market eligibility is referred without a point estimate. Invalid identity, schema or geography is rejected instead.
- Development routes do not invent a UPRN or inherit stored subject data.
- Development requests supply site coordinates; new-build status, the newest construction-age band and typical modern fabric are applied automatically.
- Customer valuation endpoints do not accept feature-attribution options.
- Confidence measures evidence strength, not probability of correctness.
- Prediction intervals are calibrated and are not fixed percentages.
Versioning
v3 is the public contract version. New valuation releases retain the same
API path and publish a new immutable release_id. Integrations should use V3,
store release IDs and obtain current limits and date windows from the release
endpoint. Values may change between releases. A release ID identifies the
valuation release, not every API software update.
For definitions used throughout these pages, see the Glossary.