> ## Documentation Index > Fetch the complete documentation index at: https://docs.auth.energy/llms.txt > Use this file to discover all available pages before exploring further. # List tariffs > Returns a summary of all tariffs offered by the specified supplier — tariff ID, display name, and when pricing data was last updated. Use this to discover available tariff IDs before fetching full pricing detail. No authentication required. ## OpenAPI ````yaml /tariff-interop/api/openapi-tariff.yaml get /v1/tariff/{mpid} openapi: 3.1.0 info: title: Tariff Interoperability API version: 0.1.1.AE description: > The Tariff Interoperability (TI) API lets Energy Smart Appliances, optimisers, and third-party services access standardised electricity tariff pricing data directly from GB energy suppliers. It is defined under the Retail Energy Code (REC) and mandated by the Smart Secure Electricity Systems (SSES) Programme. ## Two tiers of access | Tier | Who can use it | Auth required | |------|---------------|---------------| | **Public Tariff Pricing Data** | Any TI User | None | | **Consumer Specific Tariff Information** | Registered TI Users (RTI Users) with active consumer consent | OAuth 2.0 | contact: name: Auth Energy email: contact@auth.energy license: name: | © 2025 Retail Energy Code Company Ltd v0.1.0. All modifications and improves published © 2026 Auth Energy Ltd url: https://auth.energy/ servers: - url: https://register.tariff.interop description: > Central TI Register hosted by RECCo. Serves the `/v1/suppliers` and `/v1/users` endpoints only. The `v1` path prefix identifies the API version. - url: https://example-supplier.co.uk description: > Placeholder for a TI Energy Supplier's own hosted API. Each supplier runs their own instance at a URL they register with RECCo — discover it from `GET /suppliers`. Serves all `/v1/tariff`, `/v1/consent`, `/v1/webhook`, `/v1/report`, and outbound webhook endpoints. security: [] tags: - name: Registry description: >- Discover active suppliers and registered third-party users. Served by the central RECCo register. No authentication required for public data. - name: Tariffs description: >- Retrieve tariff listings and full pricing detail from a specific supplier. No authentication required. - name: Consumer Tariffs description: >- Retrieve tariff data tied to a specific consumer metering point. Requires OAuth 2.0 and active consumer consent. - name: Consent description: >- Register and revoke consumer consent linking a metering point to an RTI User via the OAuth 2.0 Authorisation Code flow. - name: Webhooks description: >- Manage webhook endpoints and receive push notifications when tariff data or consent state changes. - name: Reporting description: >- Submit periodic performance assurance metrics to RECCo (supplier obligation). paths: /v1/tariff/{mpid}: get: tags: - Tariffs summary: List tariffs description: > Returns a summary of all tariffs offered by the specified supplier — tariff ID, display name, and when pricing data was last updated. Use this to discover available tariff IDs before fetching full pricing detail. No authentication required. operationId: listTariffs parameters: - $ref: '#/components/parameters/mpidPath' - $ref: '#/components/parameters/limitParam' - $ref: '#/components/parameters/offsetParam' - name: tariff_type in: query required: false description: Filter by tariff type. schema: $ref: '#/components/schemas/TariffType' - name: fuel_type in: query required: false description: Filter by fuel type. schema: $ref: '#/components/schemas/FuelType' - name: energy_flow in: query required: false description: Filter by energy flow direction — `import` or `export`. schema: $ref: '#/components/schemas/EnergyFlow' - name: payment_method in: query required: false description: Filter by payment method. schema: $ref: '#/components/schemas/PaymentMethod' - name: ldz_region in: query required: false description: Filter by LDZ region code. Returns tariffs that include this region. schema: $ref: '#/components/schemas/LdzRegion' - name: meter_type in: query required: false description: Filter by meter type. schema: $ref: '#/components/schemas/MeterType' - name: customer_type in: query required: false description: Filter by customer type — `residential` or `business`. schema: $ref: '#/components/schemas/CustomerType' - name: valid_from in: query required: false description: | Return tariffs effective on or after this datetime (ISO 8601). Filters on `TariffDetail.valid_from`. schema: $ref: '#/components/schemas/Timestamp' - name: valid_to in: query required: false description: > Return tariffs effective up to and including this datetime (ISO 8601). Filters on `TariffDetail.valid_to`. schema: $ref: '#/components/schemas/Timestamp' responses: '200': description: A list of tariff summaries. content: application/json: schema: type: object required: - data - meta properties: data: type: array items: $ref: '#/components/schemas/TariffSummary' meta: $ref: '#/components/schemas/PaginationMeta' example: data: - tariff_id: trf_a1b2c3d4e5f67890abcdef1234567890 name: Fixed October 2026 last_modified: '2026-09-01T00:00:00.000Z' meta: total: 12 limit: 20 offset: 0 '404': $ref: '#/components/responses/NotFound' '500': $ref: '#/components/responses/InternalServerError' security: [] servers: - url: https://example-supplier.co.uk description: TI Energy Supplier API components: parameters: mpidPath: name: mpid in: path required: true description: Four-character Market Participant Identifier (MPID) of the supplier. schema: type: string minLength: 4 maxLength: 4 example: SEBD limitParam: name: limit in: query required: false description: Maximum number of records to return. Defaults to 20, maximum 100. schema: type: integer minimum: 1 maximum: 100 default: 20 example: 20 offsetParam: name: offset in: query required: false description: Number of records to skip for pagination. Defaults to 0. schema: type: integer minimum: 0 default: 0 example: 0 schemas: TariffType: type: string description: > Whether the tariff is static or dynamic. - **static** — rates in the schedule are fixed until the supplier pushes a `tariff.update` webhook event. - **dynamic** — rates change over time. RTI Users must re-fetch the schedule proactively using `valid_from` / `valid_to` on the tariff to know when to refresh. No `tariff.update` webhook events are sent for dynamic tariff rate changes. enum: - static - dynamic FuelType: type: string description: Whether the tariff applies to `electricity` or `gas`. enum: - electricity - gas example: electricity EnergyFlow: type: string description: >- Direction of energy flow — `import` into the property or `export` out of it. enum: - import - export example: import PaymentMethod: type: string description: Payment method this tariff variant applies to. enum: - direct_debit - non_direct_debit - prepayment LdzRegion: type: string description: > Local Distribution Zone (LDZ) or Network Operator region code. Identifies the geographic pricing zone for this tariff. enum: - SC - 'NO' - NE - NWT - WMD - EM - EA - NT - SO - SE - WN - WW - SW example: SE MeterType: type: string description: > Meter configuration this tariff applies to. - **single_rate** — one unit rate applies at all times (standard credit meter). - **multi_rate** — two or more unit rates apply at different times (e.g. Economy 7). - **smart** — half-hourly read smart meter, required for dynamic tariffs. - **prepayment** — prepayment meter. enum: - single_rate - multi_rate - smart - prepayment example: smart CustomerType: type: string description: Whether this tariff is available to residential or business consumers. enum: - residential - business example: residential Timestamp: type: string format: date-time description: ISO 8601 datetime with millisecond precision. example: '2026-11-01T10:00:00.000Z' TariffSummary: type: object description: >- Lightweight tariff record for listing. Fetch the full detail using `tariff_id`. required: - tariff_id - name - last_modified properties: tariff_id: $ref: '#/components/schemas/TariffId' name: type: string maxLength: 200 description: Consumer-facing display name. One name may span multiple tariff IDs. example: Comfy Cucumber October 2026 tariff_type: $ref: '#/components/schemas/TariffType' fuel_type: $ref: '#/components/schemas/FuelType' meter_type: $ref: '#/components/schemas/MeterType' customer_type: $ref: '#/components/schemas/CustomerType' last_modified: $ref: '#/components/schemas/Timestamp' PaginationMeta: type: object description: Pagination metadata included in list responses. required: - total - limit - offset properties: total: type: integer description: Total number of records matching the query. example: 47 limit: type: integer description: Maximum number of records returned in this response. example: 20 offset: type: integer description: Number of records skipped before this page. example: 0 next_offset: type: integer description: Offset to use to fetch the next page. Absent when on the last page. example: 20 TariffId: type: string format: uuid pattern: ^trf_[0-9a-f]{32}$ description: > Compact UUID generated by the supplier uniquely identifying a set of tariff pricing data prefixed with `trf_`. A single display name may map to multiple tariff IDs where a supplier prices differently by payment method or region. example: trf_a1b2c3d4e5f67890abcdef1234567890 ErrorResponse: type: object required: - code - message properties: code: type: string description: Machine-readable error code. example: tariff_not_found message: type: string description: Human-readable error description. example: No tariff found for the given tariff_id and supplier MPID. details: type: string description: Additional context to help diagnose the issue. example: >- tariff_id a1b2c3d4-e5f6-7890-abcd-ef1234567890 does not exist for supplier SEBD. responses: NotFound: description: >- 404 — The supplier MPID, tariff ID, or metering point does not exist or is not in scope. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' InternalServerError: description: 500 — Unexpected server error. Retry within the 72-hour buffer window. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' ````