> ## Documentation Index > Fetch the complete documentation index at: https://docs.arcuserp.com/llms.txt > Use this file to discover all available pages before exploring further. # Reopen an order's bill > Reopens the bill on a sales order whose invoice is issued in place so it can be corrected before it is issued again (the lines and prices of an order that has not shipped can be edited, while a change to goods already shipped goes through a return): the invoice number is retired into the order's invoice history with the reason given, the order returns to not invoiced with no invoice number, and the balance is worked out again from the payments already on the order. A posted, overdue or paid invoice is voided first in the same transaction (its revenue, tax, shipping and discount entries, and the cost of goods and stock relief of anything shipped, are reversed), which requires the key's user to hold the `accounting.post` permission, and its tax document is voided right after that transaction commits, retried later if the tax service is unreachable; nothing is refunded and no email is sent to the customer. Payments taken before the re-issue stay on the order and, in customer-deposit mode, are held as a customer deposit and applied to the invoice when it is re-issued with `POST /v1/orders/{id}/invoice`. ## OpenAPI ````yaml /openapi.yaml post /orders/{id}/invoice/reopen openapi: 3.1.0 info: title: Arcus ERP Public API version: 1.0.0 description: > Arcus ERP public REST API. Designed for external integrations and data migration. **Authentication.** Bearer token (API key) via the `Authorization` header. Format: `Authorization: Bearer ark_live_ent__` (or `ark_test_*` for sandbox). API keys are issued per-entity in **Settings > Developers > API Keys**. **Entity scoping.** The entity is encoded in the API key prefix; routes are flat (e.g. `/v1/accounts`, `/v1/orders`, `/v1/products`). A small set of platform endpoints (migration, reconciliation, events, webhook endpoints, API keys) use the `/v1/entities/{entity_id}/...` form -- those are noted in their tags. **Key capabilities.** - Related-resource hydration via `?expand[]=` (see `x-arcus-expand` on each resource). - Cursor-based pagination (`starting_after` / `ending_before` / `limit`). - Idempotency via the `Idempotency-Key` header. - Webhook events for asynchronous notification. - Conditional requests / ETag for cache validation. **Changelog.** Entries are dated and name every published contract whose MEANING moved, not only the ones whose field names changed. The narrative version of the same entries, written for integrators, is published at https://arcuserp.mintlify.app/changelog. **October 2026: the order status values are the ones the API sends.** The `Order` schema's `order_status`, `payment_status`, `fulfillment_status` and `document_type` now list the values the order endpoints actually return (`order_status`: draft, open, processing, fulfilled, cancelled, archived, expired, awaiting_ach_clearance; `payment_status`: unpaid, partial, processing, paid, refunded, terms, overdue, overpaid, partially_refunded; `fulfillment_status`: unfulfilled, partial, fulfilled, backordered, awaiting_pickup; `document_type` adds late_fee_invoice). The values themselves did not change; the schema had listed names the API never sends (`confirmed`, `partially_paid`, `partially_fulfilled`, `voided`, `on_hold`), so a client generated from it could reject a real order. On `POST /v1/orders`, `order_status` is limited to `draft` only for a `sales_order` or `invoice`. The refusals of the order, refund, settings and deposit endpoints are now listed with their `code` values on each response. **October 2026: a pair of bank lines in transit at a month end is an open item there.** `GET /v1/entities/{entity_id}/reconciliation/account-audit`, `answers.books_against_bank`, each `month_ends` row: when the two bank lines of a pair matched together to one bill payment (a wire and its return) fall on either side of that date, `bank_unbooked_amount` and `bank_unbooked_count` now include the line already in the bank, and `gl_uncleared_amount` and `gl_uncleared_count` include the payment's bank leg; `explained_by_open_items` therefore explains that date instead of leaving the part in transit unexplained. No field is renamed and no other date moves; once both lines are in the bank the pair counts nowhere, as every other match. **2026-09-22 (planned 2026-09-21), REORDER-BUYER-TRUTH: demand changed what it MEANS on three published contracts, with no field renamed.** An integrator that pins field names sees no breakage and different numbers, which is why this entry exists. - **Demand now counts build consumption.** `demand_avg_per_day` on the public product, kit and inventory-balance objects, and `daily_demand` / `demand_basis` / `net_suggested_qty` on `GET /v1/purchasing/reorder-report`, are composed from fulfilled sales lines PLUS posted `build_consume` inventory draws: each physical decrement of a product counts exactly once. The previous rule adopted an internal-consumption basis only when the sales blend was exactly zero, so a product both sold AND consumed into work orders planned as if the build draws did not exist. Products drawn into work orders move; on one production-shaped dataset five did, the largest from 0.05/day to 14.95/day. - **`demand_basis` now carries four values, not two:** `sales`, `sales_and_builds`, `builds` and `consumption`. A consumer with a two-branch reader (anything that is not `consumption` is `sales`) silently hides the two new ones. - **`current_demand_units` on `GET /v1/inventory/balances/:id` moved, by a second rule.** It counts committed-but-unshipped CUSTOMER demand, and it now counts a kit component's own line rather than its parent kit line, and excludes non-sales documents. On one production dataset 269 of 1,043 balance rows changed, 227 of them downward; the largest single move was 1,941 to 25, on a product whose open PURCHASE order line had been reported as customer demand. Re-baseline anything that alerts or reorders off this field. - `run_rate_30/90/180/365` and `blended_daily` on the same balance object move for the first reason above. - **Added, not changed:** `GET /v1/purchasing/reorder-report` accepts `demand_window` and returns the unit, cover-through and reorder-point-provenance fields documented on that operation; `order_multiple` is accepted and returned on the product-vendor doors. - **Volume note.** The `inventory.low_stock`, `inventory.out_of_stock` and `inventory.back_in_stock` webhook events are population-gated on `on_hand <= reorder_point`, and reorder points move with the demand above, so subscribers should expect a one-time step change in event volume around the release. servers: - url: https://api.arcuserp.com/v1 description: Arcus ERP API (accepts both live `ark_live_*` and test `ark_test_*` keys) - url: https://dev-api.arcuserp.com/v1 description: >- Dev sandbox API (test-only data, accepts `ark_test_*` keys against dev RDS) security: [] paths: /orders/{id}/invoice/reopen: parameters: - name: id in: path required: true schema: type: string format: uuid post: tags: - Orders summary: Reopen an order's bill description: >- Reopens the bill on a sales order whose invoice is issued in place so it can be corrected before it is issued again (the lines and prices of an order that has not shipped can be edited, while a change to goods already shipped goes through a return): the invoice number is retired into the order's invoice history with the reason given, the order returns to not invoiced with no invoice number, and the balance is worked out again from the payments already on the order. A posted, overdue or paid invoice is voided first in the same transaction (its revenue, tax, shipping and discount entries, and the cost of goods and stock relief of anything shipped, are reversed), which requires the key's user to hold the `accounting.post` permission, and its tax document is voided right after that transaction commits, retried later if the tax service is unreachable; nothing is refunded and no email is sent to the customer. Payments taken before the re-issue stay on the order and, in customer-deposit mode, are held as a customer deposit and applied to the invoice when it is re-issued with `POST /v1/orders/{id}/invoice`. operationId: reopenOrderBillV1 parameters: - $ref: '#/components/parameters/IdempotencyKey' requestBody: required: true content: application/json: schema: type: object required: - reason properties: reason: type: string minLength: 10 description: >- Why the bill is being re-opened. At least 10 characters after trimming; kept with the retired invoice. expect: type: object description: >- The order as the caller last read it. When any named field has changed the endpoint returns 409 `reopen_pre_image_moved` and changes nothing. properties: invoice_number: type: string order_total: type: number amount_paid: type: number responses: '200': description: The bill is re-opened (or was already re-opened, `changed` false). content: application/json: schema: type: object properties: data: type: object properties: order: $ref: '#/components/schemas/Order' changed: type: boolean voided_first: type: boolean description: >- True when a live invoice was voided before it was retired. retired_invoice_number: type: string nullable: true history_id: type: string format: uuid nullable: true target: type: string nullable: true enum: - in_place - per_shipment_parent payment_status_before: type: string nullable: true payment_status_after: type: string nullable: true '403': $ref: '#/components/responses/Error' '404': $ref: '#/components/responses/Error' '409': description: > `reopen_pre_image_moved`: the order changed since the caller read it. `open_rma_blocks_void`: an open return references the order, so its live invoice cannot be voided. `retire_pre_image_moved`: the invoice header moved while it was being retired. content: application/json: schema: $ref: '#/components/schemas/Error' '422': description: > `reopen_reason_required`: the reason is missing or shorter than 10 characters. `invoice_not_issued`: the order carries no invoice to re-open. `terminal_order_keeps_voided`: a cancelled, archived, expired or voided order keeps its voided invoice. `retire_scoped_to_in_place_invoice`: the document is a child invoice of another order. `retire_scoped_to_sales_order` / `historical_import_not_retirable`: only a native sales order's bill is re-opened. `period_closed` / `recognition_already_reversed`: the live invoice cannot be voided (the void's own refusals). content: application/json: schema: $ref: '#/components/schemas/Error' security: - ApiKeyAuth: - orders:write components: parameters: IdempotencyKey: name: Idempotency-Key in: header required: false description: > Client-generated unique key for idempotent POST/PATCH/DELETE operations. Alias for the Idempotency parameter. Max 255 chars. On retry with the same key, the original response is returned without re-executing the operation. Keys expire after 24 hours. A second request with the same key sent while the first is still running waits for it and returns its answer; if the first is still running after 20 seconds the second answers 409 `idempotency_key_in_use` (retryable, nothing done). An answer carrying `retryable: true` is not cached. Reusing a key with a different request body answers 409 `idempotency_key_collision` (nothing done; send the new request with a fresh key). The replay, the wait and these two 409 codes come from the idempotency layer, so they apply to the operations that run it, each of which can answer the two codes whether or not its own 409 response lists them. The handlers of these operations take the header but do not run the layer, so on them the key neither replays nor answers either code: createPaymentPlan, chargePaymentPlanInstallment, setProductLocations, updateOrder, emailOrder, updateOrderItem, confirmPickup, markOrderNoShow, applyExistingPaymentToInvoices, updatePackage, movePackageItem, changePackageBox, changePackageCarrier, voidPackageLabel, printPackageLabel, emailPackage, setProNumberV1, setPackageProNumber, sendPurchaseOrderToVendorV1, notifyRevisionPurchaseOrderV1, addMaintenanceLog, generateBOLV1, createReportJobV1 and customerAcknowledgeRevision; recordVendorPrepaymentV1 and recordCustomerDepositV1 hand the key to their own write instead. schema: type: string maxLength: 255 schemas: Order: type: object description: > An Arcus ERP order document. One table holds quotes, sales_orders, invoices, returns, and purchase_orders -- always filter by document_type. entity_id is always from the API key (Layer 1 isolation). properties: id: type: string format: uuid object: type: string enum: - order entity_id: type: string format: uuid readOnly: true order_number: type: string readOnly: true document_type: type: string enum: - quote - sales_order - invoice - return - purchase_order - late_fee_invoice order_status: type: string enum: - draft - open - processing - fulfilled - cancelled - archived - expired - awaiting_ach_clearance payment_status: type: string enum: - unpaid - partial - processing - paid - refunded - terms - overdue - overpaid - partially_refunded fulfillment_status: type: string enum: - unfulfilled - partial - fulfilled - backordered - awaiting_pickup account_id: type: string format: uuid nullable: true location_id: type: string format: uuid nullable: true po_number: type: string nullable: true order_date: type: string format: date-time nullable: true due_date: type: string format: date-time nullable: true subtotal: type: number discount_total: type: number shipping_total: type: number tax_total: type: number fee_total: type: number order_total: type: number list_price_total: type: number readOnly: true description: >- Derived (display-only): SUM(list_price * qty) over non-kit lines. The gross baseline of the gross-to-net bridge (List price minus pricing_savings equals subtotal). Never part of order_total. pricing_savings: type: number readOnly: true description: >- Derived (display-only): SUM(pricing_rule_adjustment * qty) over non-kit lines (positive magnitude). Per-unit pricing-rule savings already baked into subtotal via sell_rate (ASC 606 transaction price); shown as an informational List-to-Subtotal bridge, never subtracted from order_total. amount_paid: type: number readOnly: true description: 'SSOT: utils/ar-helpers.mjs::updateARBalance. Do not write directly.' balance_due: type: number readOnly: true description: >- AR receivable (the amount this document is owed AS A RECEIVABLE). Forced to 0 on DRAFT sales documents, on cancelled / archived / expired orders, and on voided or fully-refunded invoices, because none of those carries a receivable: a draft is not a receivable, and a terminal document owes nothing. This is the number that ties to AR aging, the AR outstanding total, and the GL AR control account. For the amount still COLLECTIBLE on any document at any status (including a draft), use `amount_due`. Purchase orders and quotes are never forced to 0. SSOT: utils/ar-helpers.mjs::updateARBalance. Do not write directly. amount_due: type: number readOnly: true description: >- Collectible remainder: order_total minus amount_paid, rounded to 2 decimals. Status-blind BY DESIGN, so it answers "how much is still OUTSTANDING on this document as simple arithmetic" even where `balance_due` is 0 because the document is not (yet) a receivable. Negative when the customer has overpaid (money owed back to them). On a confirmed, non-refunded document with no sales allowance and no cancellation, `amount_due` and `balance_due` are equal. NOT A PAYABLE AMOUNT. Because it is status-blind it stays positive on documents that can accept no payment at all -- a cancelled / archived / expired order, a voided invoice, a fully-refunded order -- and it OVERSTATES what is owed on an allowance-settled order (a standalone concession refund reversed goods or tax: `balance_due` correctly settles to 0 while the remainder does not). Collecting `amount_due` on either shape creates an overpayment, and the payment endpoints will refuse it with `order_not_payable` (422). To decide how much to collect, take the amount from the payment surface you are about to call (`POST /v1/orders/{id}/payments` validates and caps server-side); to reconcile against AR aging or the GL AR control account, use `balance_due`. tax_exempt: type: boolean delivery_option: type: string enum: - ship - pick_up - local_delivery notes: type: string nullable: true internal_notes: type: string nullable: true invoice_number: type: string nullable: true readOnly: true invoice_type: type: string enum: - order - manual - proforma - correction nullable: true is_on_hold: type: boolean readOnly: true hold_type: type: string nullable: true readOnly: true ship_complete: type: boolean source_platform: type: string nullable: true external_order_id: type: string nullable: true external_order_number: type: string nullable: true metadata: type: object nullable: true created_at: type: string format: date-time readOnly: true updated_at: type: string format: date-time readOnly: true Error: description: | Alias for ErrorEnvelope. Canonical error response shape used by all API endpoints. Refer to ErrorEnvelope for the full field definition. allOf: - $ref: '#/components/schemas/ErrorEnvelope' ErrorEnvelope: type: object description: | Canonical error response envelope. All API errors use this shape. required: - error - code properties: error: type: string description: Machine-readable error key example: not_found code: type: string description: Machine-readable error code (often same as error) example: not_found type: type: string enum: - validation_error - permission_error - not_found - conflict - rate_limit - internal - expand_error - not_implemented example: not_found hint: type: string description: Human-readable one-sentence explanation (English) example: >- The requested order does not exist or does not belong to this entity. param: type: string description: The parameter that caused the error, if applicable example: expand[0] required: type: string description: The scope required (only on insufficient_scope errors) example: accounts:read request_id: type: string description: >- Unique request ID for support tracing (maps to CloudWatch log stream) example: req_abc123 responses: Error: description: Error response (400/401/403/404/409/422/429/500) content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' securitySchemes: ApiKeyAuth: type: http scheme: bearer description: | API key issued per entity via Settings > Developers > API Keys. Each key carries scopes (e.g. orders:read, products:write). Bearer token format: Authorization: Bearer ark_live_ent__ Test keys use ark_test_ent__. Both are issued per entity via Settings > Developers > API Keys. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.