> ## Documentation Index > Fetch the complete documentation index at: https://docs.lumenaza.de/llms.txt > Use this file to discover all available pages before exploring further. # Trigger Installment Update > Allows the customer to submit a change to the installment plan either by providing the amount in euro per month or in kWh per year. The post updates the annual_consumption property of the customer contracts and triggers an installment re-calculation. If the amount is provided in euro per month, the annual consumption is calculated from the working price of the customer's product. ## OpenAPI ````yaml /lumx_openapi.yaml post /v3/consumers/{userID}/contracts/{contractID}/trigger_installment_update/ openapi: 3.0.3 info: title: Lumenaza external API version: 3.8.0 (v3) description: Specification of the Lumenaza external API. servers: - url: https://api.lumenaza.de/ description: Produktivserver - url: https://api.test.lumenaza.de/ description: Testserver security: [] tags: - name: Community Data API description: >- The API is used to retrieve master data and measurement data for a community. A community is defined by all customers that belong to your company - name: Consumer API description: >- Manage consumers, their contracts, products, readings, and charges or credits - name: Consumption Forecast API description: Retrieve consumption forecasts for grid contracts - name: Customer Portal API description: Request a customer portal password reset - name: Customer API description: Retrieve product and pricing information for a customer contract - name: Files API description: Upload files and receive identifiers for use in other API requests - name: Market Partner API description: List market partners and retrieve market partner bills and payment advices - name: Master Data API description: Submit and track changes to customer and redispatch master data - name: Migration API description: Migrate consumer contracts and add contracts during migration - name: Offer Calculator API description: Calculate customer offers for a tariff and the supplied parameters - name: Price Calculator API description: >- Retrieve day-ahead electricity prices, local utility prices, and estimated CO₂ savings - name: Producer API description: >- Manage producers, their contracts, plants, feed-in data, and charges or credits - name: User Documents API description: List and retrieve documents associated with users and their contracts - name: Validation API description: >- Validate market location identifiers, IBANs, and preferred delivery start dates paths: /v3/consumers/{userID}/contracts/{contractID}/trigger_installment_update/: post: tags: - Consumer API summary: Trigger Installment Update description: >- Allows the customer to submit a change to the installment plan either by providing the amount in euro per month or in kWh per year. The post updates the annual_consumption property of the customer contracts and triggers an installment re-calculation. If the amount is provided in euro per month, the annual consumption is calculated from the working price of the customer's product. operationId: trigger_installment_update parameters: - in: path name: contractID schema: type: string required: true - in: path name: userID schema: type: string required: true requestBody: content: application/json: schema: $ref: '#/components/schemas/ContractInstallmentUpdate' application/x-www-form-urlencoded: schema: $ref: '#/components/schemas/ContractInstallmentUpdate' multipart/form-data: schema: $ref: '#/components/schemas/ContractInstallmentUpdate' required: true responses: '200': content: application/json: schema: $ref: '#/components/schemas/ContractInstallmentUpdateResponse' examples: SuccessfulResponse: value: contract_id: '123456' user_id: '789012' detail: Installment update successful. summary: Example of a successful installment update response description: '' '400': content: application/json: schema: oneOf: - type: object additionalProperties: type: array items: type: string example: email: - Enter a valid email address. non_field_errors: - Invalid combination of fields. - $ref: '#/components/schemas/DetailResponse' examples: BadRequest-InvalidUnit: value: detail: Invalid unit provided. summary: Example of a bad request due to invalid unit provided BadRequest-InstallmentValueLowerThanBaseFee: value: detail: Installment value is lower than base fee gross price summary: >- Example of a bad request due to installment value being lower than base fee gross price BadRequest-NoActiveTariffFound: value: detail: No active Tariff found for contract 123456 summary: >- Example of a bad request due to no active tariff found for the contract description: Field-validation errors or installment update business-rule errors. '404': content: application/json: schema: $ref: '#/components/schemas/NotFoundResponse' examples: NotFound-ContractNotFound: value: detail: Contract not found. summary: Example of a not found response due to contract not found description: The runtime contract lookup could not find the requested contract. components: schemas: ContractInstallmentUpdate: type: object properties: unit: $ref: '#/components/schemas/ContractInstallmentUpdateUnitEnum' amount: type: integer minimum: 0 required: - amount - unit ContractInstallmentUpdateResponse: type: object properties: contract_id: type: string user_id: type: string detail: type: string required: - contract_id - detail - user_id DetailResponse: type: object properties: detail: type: string required: - detail NotFoundResponse: type: object properties: detail: type: string required: - detail ContractInstallmentUpdateUnitEnum: enum: - kwh_per_year - cent_per_month type: string description: |- * `kwh_per_year` - kWh pro Jahr * `cent_per_month` - Cent pro Monat ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.