> ## Documentation Index > Fetch the complete documentation index at: https://docs.dolfinai.co/llms.txt > Use this file to discover all available pages before exploring further. # Cancel purchase order > Mark a purchase order as void (terminal Cancelled). Stops future matching but keeps existing allocations. Already-terminal orders are rejected. ## OpenAPI ````yaml /api-reference/openapi.json post /purchase-orders/{id}/cancel openapi: 3.1.1 info: title: Dolfin API description: >- Dolfin API for AR & AP. Authenticate using the `x-dolfin-api-key` header with the API key distributed to your organisation. version: v1 servers: - url: https://api.dolfinai.co description: Production security: - {} tags: - name: Webhooks - name: Users - name: TaxRates - name: Suppliers - name: Supplier Credit Notes - name: Bills - name: SpendCategories - name: Payables - name: RecurringInvoices - name: Receivables - name: Purchase Orders - name: Products - name: Payments - name: Invoices - name: Organisations - name: Members - name: MCP - name: Matching - name: Invoice Reminders - name: Industries - name: Gmail - name: Delivery Notes - name: Customers - name: Currencies - name: Credit Notes - name: Clients - name: ClientInvites - name: BankPayments - name: Bank details - name: Auth - name: ApprovalPolicies - name: ApiKeys - name: Agent paths: /purchase-orders/{id}/cancel: post: tags: - Purchase Orders summary: Cancel purchase order description: >- Mark a purchase order as void (terminal Cancelled). Stops future matching but keeps existing allocations. Already-terminal orders are rejected. parameters: - name: id in: path required: true schema: type: string format: uuid responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/PurchaseOrderResponse' '403': description: >- Organisation.InsufficientRole — caller's organisation role is below the level this action requires content: application/problem+json: schema: $ref: '#/components/schemas/ProblemDetails' '404': description: >- PurchaseOrder.NotFound — purchase order does not exist or belongs to another organisation content: application/problem+json: schema: $ref: '#/components/schemas/ProblemDetails' '409': description: >- PurchaseOrder.AlreadyTerminal — the purchase order is already closed or cancelled and cannot change status content: application/problem+json: schema: $ref: '#/components/schemas/ProblemDetails' components: schemas: PurchaseOrderResponse: required: - poNumber - currency type: object properties: id: type: string description: Unique identifier of the purchase order. format: uuid organisationId: type: string description: The organisation that owns the purchase order. format: uuid supplierId: type: - 'null' - string description: The supplier the order is raised against, if assigned. format: uuid externalRef: type: - 'null' - string description: >- Caller's own reference for the order (a reverse pointer to the platform's record), if any. poNumber: type: string description: >- Human purchase-order number printed on the order. Required and unique within the organisation. currency: type: string description: ISO 4217 currency code of the order. status: $ref: '#/components/schemas/PurchaseOrderStatus' description: >- Lifecycle status: Draft, Open, PartiallyMatched, FullyMatched (all derived from matching), or the manual terminal states Closed / Cancelled. orderDate: type: - 'null' - string description: Date the order was raised, if recorded. format: date-time expectedDeliveryDate: type: - 'null' - string description: Expected delivery date, if recorded. format: date-time lines: type: array items: $ref: '#/components/schemas/PurchaseOrderLineResponse' description: The ordered lines, in display order. createdAt: type: string description: When the purchase order was created. format: date-time updatedAt: type: string description: When the purchase order was last updated. format: date-time description: A purchase order and its ordered lines. ProblemDetails: type: object properties: type: type: - 'null' - string title: type: - 'null' - string status: pattern: ^-?(?:0|[1-9]\d*)$ type: - 'null' - integer - string format: int32 detail: type: - 'null' - string instance: type: - 'null' - string PurchaseOrderStatus: enum: - Draft - Open - PartiallyMatched - FullyMatched - Closed - Cancelled description: >- Lifecycle status of a purchase order. Draft, Open, PartiallyMatched and FullyMatched are derived from matching (and reverse as allocations change); Closed and Cancelled are manual terminal states a human sets. PurchaseOrderLineResponse: required: - description type: object properties: id: type: string description: Unique identifier of the line. format: uuid description: type: string description: Line description. sku: type: - 'null' - string description: >- Product SKU, used as the exact-match key against bill lines. Optional. quantityOrdered: pattern: ^-?(?:0|[1-9]\d*)(?:\.\d+)?$ type: - number - string description: Quantity ordered on this line. format: double unit: type: - 'null' - string description: Unit of measure (e.g. each, kg), if recorded. unitPrice: pattern: ^-?(?:0|[1-9]\d*)(?:\.\d+)?$ type: - number - string description: Ordered unit price (ex-tax). format: double taxRate: pattern: ^-?(?:0|[1-9]\d*)(?:\.\d+)?$ type: - number - string description: Tax rate applied to the line, as a percentage. format: double taxAmount: pattern: ^-?(?:0|[1-9]\d*)(?:\.\d+)?$ type: - number - string description: Tax amount for the line. format: double subTotal: pattern: ^-?(?:0|[1-9]\d*)(?:\.\d+)?$ type: - number - string description: Net (ex-tax) line total. format: double sortOrder: pattern: ^-?(?:0|[1-9]\d*)$ type: - integer - string description: Display order of the line within the order. format: int32 matchedQuantity: pattern: ^-?(?:0|[1-9]\d*)(?:\.\d+)?$ type: - 'null' - number - string description: >- Total quantity matched against this line across all bills. Null on list responses (not computed there); populated on the detail (get-by-id) response. format: double fullyMatched: type: - 'null' - boolean description: >- True once the matched quantity covers the whole ordered quantity. Null when MatchedQuantity is not computed (list responses) — null means 'unknown', not 'unmatched'. description: A single ordered line on a purchase order. ````