> ## Documentation Index > Fetch the complete documentation index at: https://docs.wellapp.ai/llms.txt > Use this file to discover all available pages before exploring further. # Patch Invoice items > Create a new invoice item with detailed product information, pricing, taxes, and period specifications. ## OpenAPI ````yaml PATCH /v1/invoice-items/{id} openapi: 3.1.0 info: title: Well Document API version: 1.0.0 description: API for uploading and managing financial documents in the Well platform servers: - url: https://api.wellapp.ai security: [] paths: /v1/invoice-items/{id}: patch: summary: Create an invoice item description: >- Create a new invoice item with detailed product information, pricing, taxes, and period specifications. parameters: - $ref: '#/components/parameters/AuthorizationHeader' requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/InvoiceItemPatch' example: type: invoice_item attributes: line_id: '1' sku: WM-1001 name: Wireless Mouse description: Ergonomic wireless mouse with USB receiver unit_price: 25 currency: EUR unit: EA min_quantity: 1 max_quantity: 500 tax: rate: 20 category: standard scheme: VAT period: start: '2025-06-26' end: '2025-06-27' relationships: invoices: data: - type: invoice id: invoice1 responses: '201': description: Invoice item created successfully content: application/json: schema: $ref: '#/components/schemas/InvoiceItem' example: data: type: invoice_item id: item_001 attributes: line_id: '1' sku: WM-1001 name: Wireless Mouse description: Ergonomic wireless mouse with USB receiver unit_price: 25 currency: EUR unit: EA min_quantity: 1 max_quantity: 500 tax: rate: 20 category: standard scheme: VAT period: start: '2025-06-26' end: '2025-06-27' created_at: '2025-05-11T13:42:12Z' updated_at: '2025-05-11T13:45:20Z' relationships: invoices: data: - type: invoice id: invoice1 medias: data: - type: media id: media-1 included: - type: invoice id: invoice1 attributes: reference_number: INV-2025-001 document_type: commercial_invoice document_type_code: '380' issue_date: '2025-01-15' due_date: '2025-02-15' local_currency: EUR local_totals: subtotal: '1000.00' tax_total: '200.00' total_amount: '1200.00' terms: Payment due within 30 days billing_context: subscription payment_status: paid: false amount_paid: 0 amount_remaining: 1200 status: draft description: Professional services invoice for January 2025 created_at: '2025-01-15T10:30:00Z' updated_at: '2025-01-15T10:30:00Z' - type: media id: media-1 attributes: media_type: logo is_primary: true url: >- https://cdn.example.com/product-images/wireless-mouse.jpg created_at: '2025-05-11T13:00:00Z' updated_at: '2025-05-11T13:00:00Z' '400': description: Bad request - validation error content: application/json: schema: $ref: '#/components/schemas/BadRequestError' '401': description: Unauthorized - invalid API key content: application/json: schema: $ref: '#/components/schemas/UnauthorizedError' components: parameters: AuthorizationHeader: name: Authorization in: header required: true schema: type: string description: Bearer token for authentication schemas: InvoiceItemPatch: type: object description: Request schema for creating invoice items properties: data: type: object properties: type: type: string const: invoice_item description: Resource type identifier attributes: type: object properties: line_id: type: string description: Line identifier within the invoice example: '1' sku: type: string description: Stock Keeping Unit identifier example: WM-1001 name: type: string description: Product or service name example: Wireless Mouse description: type: string description: Detailed description of the item example: Ergonomic wireless mouse with USB receiver unit_price: type: number format: decimal minimum: 0 description: Unit price in local currency example: 25 currency: type: string pattern: ^[A-Z]{3}$ description: ISO 4217 currency code example: EUR unit: type: string enum: - EA - HUR - KGM - ... description: >- Unit of measurement. See [all available units](/enums/invoice-line-unit) for complete list. example: EA min_quantity: type: integer minimum: 0 description: Minimum quantity allowed example: 1 max_quantity: type: integer minimum: 1 description: Maximum quantity allowed example: 500 tax: type: object properties: rate: type: number format: decimal minimum: 0 maximum: 100 description: Tax rate as percentage example: 20 category: type: string enum: - standard - reduced - exempt - ... description: >- Tax category classification. See [all tax categories](/enums/tax-cat) for complete list. example: standard scheme: type: string enum: - VAT - EU_VAT - UK_VAT - ... description: >- Tax scheme classification. See [all tax schemes](/enums/tax-scheme) for complete list. example: VAT period: type: object properties: start: type: string format: date description: Service period start date example: '2025-06-26' end: type: string format: date description: Service period end date example: '2025-06-27' relationships: type: object properties: invoices: type: object properties: data: type: array items: type: object properties: type: type: string const: invoice id: type: string format: uuid medias: type: object properties: data: type: array items: type: object properties: type: type: string const: media id: type: string format: uuid InvoiceItem: type: object description: Response schema for invoice items properties: type: type: string const: invoice_item description: Resource type identifier id: type: string format: uuid description: Unique identifier for the invoice item attributes: $ref: '#/components/schemas/InvoiceItemsAttributes' relationships: type: object properties: invoices: type: object properties: data: type: array items: type: object properties: type: type: string const: invoice id: type: string format: uuid description: Related invoices medias: type: object properties: data: type: array items: type: object properties: type: type: string const: media id: type: string format: uuid description: Related media files BadRequestError: type: object properties: code: type: string example: SCHEMA_VALIDATION_ERROR description: Error code identifier status: type: integer example: 400 description: HTTP status code title: type: string example: Validation Error description: Error title message: type: string example: The request is invalid description: Detailed error message details: type: array items: type: object properties: instancePath: type: string description: Path to the invalid field in the request schemaPath: type: string description: Path to the validation rule in the schema keyword: type: string description: Validation keyword that failed params: type: object description: Parameters related to the validation failure message: type: string description: Human-readable validation error message description: Array of detailed validation errors meta: type: object properties: log_id: type: string format: uuid example: 65c669d4-679c-4a8b-b8c0-fbe37699bb5b description: Unique identifier for tracking this error in logs required: - log_id required: - code - status - title - message - meta UnauthorizedError: type: object properties: code: type: string example: UNAUTHORIZED description: Error code identifier status: type: integer example: 401 description: HTTP status code title: type: string example: Unauthorized description: Error title message: type: string example: You are not authorized to access this resource description: Detailed error message meta: type: object properties: log_id: type: string format: uuid example: 65c669d4-679c-4a8b-b8c0-fbe37699bb5b description: Unique identifier for tracking this error in logs required: - log_id required: - code - status - title - message - meta InvoiceItemsAttributes: type: object properties: line_id: type: string description: Line identifier within the invoice example: '1' sku: type: string description: Stock Keeping Unit identifier example: WM-1001 name: type: string description: Product or service name example: Wireless Mouse description: type: string description: Detailed description of the item example: Ergonomic wireless mouse with USB receiver unit_price: type: number format: decimal minimum: 0 description: Unit price in local currency example: 25 currency: type: string pattern: ^[A-Z]{3}$ description: ISO 4217 currency code example: EUR unit: type: string description: Unit of measurement example: EA min_quantity: type: integer minimum: 0 description: Minimum quantity allowed example: 1 max_quantity: type: integer minimum: 1 description: Maximum quantity allowed example: 500 tax: type: object properties: rate: type: number format: decimal minimum: 0 maximum: 100 description: Tax rate as percentage example: 20 category: type: string description: Tax category example: standard scheme: type: string description: Tax scheme identifier example: VAT period: type: object properties: start: type: string format: date description: Service period start date example: '2025-06-26' end: type: string format: date description: Service period end date example: '2025-06-27' created_at: type: string format: date-time description: Creation timestamp example: '2025-05-11T13:42:12Z' updated_at: type: string format: date-time description: Last update timestamp example: '2025-05-11T13:45:20Z' ````