---
title: "Credit Ar Invoice"
method: POST
path: "/companies/{company_id}/ar/invoices/{invoice_id}/credit-note"
tags: ["ar-invoices"]
---

# Credit Ar Invoice

`POST /companies/{company_id}/ar/invoices/{invoice_id}/credit-note`

## Request

- Base URL: `https://app.zeno-works.ch` (the document declares no server; this is the origin it was published from)
- URL: `https://app.zeno-works.ch/companies/{company_id}/ar/invoices/{invoice_id}/credit-note`
- Auth: none declared

Fully credit an issued invoice: create a credit-note document — carrying a copy of
the credited invoice's lines — and reverse the original's posting (AR + output VAT +
open item back out) through the guarded storno door. Partial credits are a follow-up.

**Dated** ``body.posting_date``, else today (never before the invoice): the credit
note is printed with that date and its VAT reduction is declared in that date's VAT
window — the credited invoice's output VAT is backed out of the MWST-Abrechnung, not
just out of the ledger. The invoice's posted **dunning fees** are reversed with it.

Once the customer has paid, the cash actually received (fees included) is additionally
posted as its own opposite-direction ``credit_note`` document against the **AP**
control account: that gives the refund an open item a bank payment can settle
(``ar.service`` §credit note).

Refusals: **422** when the invoice is not ``issued``, is itself a credit note, was
already credited, or carries a **write-off** (a written-off invoice cannot be
credited); **422** when ``posting_date`` predates the invoice or a dunning fee or
payment the credit undoes, or when no **open** accounting period covers the credit's
date — **re-send with a ``posting_date`` in an open period** (or open the fiscal year);
**422** when a posted recognition installment would have to be reversed in a closed
period (reopen that period; no date clears it); **409** when the credit's date falls in
a ``filed``/``paid`` VAT period — **re-send with a ``posting_date`` in an open VAT
period**.

## Path parameters

- `company_id` string, required
- `invoice_id` string, required

## Headers

- `authorization` string, nullable

## Cookies

- `access_token` string, nullable

## Request body

- ArInvoiceCredit: ``POST …/ar/invoices/{id}/credit-note`` body — optional, all fields optional. ``posting_date`` is the credit note's own date (ZENO-223): the date it is printed with, and the date of the reversal, its VAT reduction and any refund leg. Omitted: today (the day the credit is granted), never earlier than the credited invoice. A credit refused because that date falls in a **filed** VAT window (409) is cleared by re-sending it with a ``posting_date`` in an open window.
  - `posting_date` string, date, nullable

## Response `201`

Successful Response

- ArInvoiceDetailOut
  - `doc_type` 'invoice' | 'credit_note'
  - `counterparty_id` string, nullable
  - `issuer_profile_id` string, nullable
  - `issue_date` string, date, required
  - `due_date` string, date, nullable
  - `service_period_start` string, date, nullable
  - `service_period_end` string, date, nullable
  - `currency` string
  - `language` string, required
  - `payment_terms_id` string, nullable
  - `invoice_discount_kind` 'none' | 'percent' | 'amount'
  - `invoice_discount_value` string
  - `footer_text` string, nullable
  - `legal_text` string, nullable
  - `notes` string, nullable
  - `credited_invoice_id` string, nullable
  - `id` string, required
  - `status` 'draft' | 'issued' | 'cancelled', required: Editorial lifecycle owned by ``ar_invoice`` (paid/overdue are derived on read from the linked ``gl_open_item``, not stored here).
  - `origin` 'human' | 'system' | 'ai' | 'api' | 'mcp' | 'chat': What KIND of actor posted a journal entry — the attribution flag. Two axes in one vocabulary, because the column answers one question — *can a reader take this as a person's own judgement?* **Authorship** — the value says who composed the booking: * ``ai`` = the AI-accountant composed it (an autonomous post, or a one-click accept where the content is still the accountant's proposal); * ``system`` = a mechanical/background ``SystemPrincipal`` post (migrations, close automation, deterministic seeds). **Channel** — the value says which surface a person's own action arrived through, because "a ``UserPrincipal`` acted" is NOT the same claim as "a person decided". All four are derived from the request edge by :func:`~invoiage_db.repos.gl_posting._resolve_origin`: * ``human`` = an interactive browser session (cookie/JWT auth). The only value that asserts a person was looking at the screen; * ``mcp`` = an API-key request carrying the mcp shell's ``X-Zeno-Surface`` marker — a connected agent, which MAY be relaying a person and may not; * ``api`` = any other API-key request (a script, an integration, an agent calling the REST api directly). Not provably a person either; * ``chat`` = the built-in CFO chat relaying a person's approval in-app. Its *authored* bookings stamp ``ai``; ``chat`` is only for the relay. Widening this vocabulary is a **one-way door on rollback**: the PG type is a native enum converted at load (``pg_enums._pg_enum``), so an api whose Python enum lacks a value raises ``LookupError`` reading any row that carries it. See the ``0112`` migration.
  - `document_no` string, nullable
  - `commercial_document_id` string, nullable
  - `snapshot_document_id` string, nullable
  - `net_total` string, required
  - `vat_total` string, required
  - `gross_total` string, required
  - `payment_status` string, nullable
  - `open_amount` string, nullable
  - `is_overdue` boolean
  - `posting` ItemPostingOut: The ledger projection of one ingested document — the posted/not marker. Present only on the surfaces that project it (the item lists and the item detail read, ZCT-848); everywhere else ``ItemOut.posting`` stays ``None``, which means "not computed here", NOT ``unposted``. Never branch on a missing value. It answers "is it in the journal?", not "may I code it?": a coding row posted without an entry, or an expense-receipt routing row, reads ``unposted`` here while coding the item is still refused as already booked (``gl_autopost.coding_blocker``). ``accounts`` is filled only for :attr:`ItemPostingStatus.posted` and holds **every** operating leg, largest first — a document split across three expense accounts has no single answer, and silently showing the first line would be a lie. It may legitimately be empty (an entry with only control/VAT legs).
    - `status` 'posted' | 'reversed' | 'held' | 'unposted', required: Where an ingested document stands in the general ledger (ZET-98/103/108). Deliberately NOT a boolean: a boolean collapses four states a treuhänder has to tell apart, and "not posted" alone cannot say *why*. - ``posted`` — a coding decision for this document points at a journal entry whose ``status`` is ``posted``. This is the only value that means "it is in the ledger"; :attr:`ItemPostingOut.accounts` says where. - ``reversed`` — the document was booked and that entry was reversed. The ledger no longer carries it, so it is **not** posted (ZET-95), but it is a materially different state from "never touched": it needs re-booking. - ``held`` — the AI accountant produced a coding proposal that did not clear the autonomy policy and is waiting for a human. Nothing is in the ledger. - ``unposted`` — everything else: no coding decision at all, a shadow-mode decision (``assist``: it *would* have posted but did not), or a decision of a kind that books nothing.
    - `journal_entry_id` string, nullable
    - `accounts` ItemPostingAccountOut[]
      - `account_id` string, required
      - `code` string, required
      - `name` string, required
      - `amount` string, required
    - `coding_pending` boolean
    - `filed_with` ItemFiledWithOut: The booking a re-ingested COPY of an invoice was filed with (ZEN-1, ZCT-945). The coder's dunning linkage (``ap_dunning.try_link_ap_document``) recognises a second upload of an invoice that is already booked and files it against that booking's open item instead of booking it twice. It writes no decision, so the copy's own projection is ``unposted`` and the lists used to read "Not posted" — to the reader the AI looked as if it had stopped posting. This names the booking the copy belongs to. Set only where "already booked" is TRUE (:func:`services.item_posting.posting_map`): an advisory, non-reminder, non-collision link whose holder entry is posted, and — for the weaker payment-reference tier — only for a copy dated like the booked invoice. ``gross`` / ``currency`` are the BOOKED document's; ``amount_differs`` says the copy prints another total or currency, so the reader checks the booking rather than trusting the badge (the linker matches amounts within a band, not exactly).
      - `journal_entry_id` string, required
      - `entry_no` string, nullable
      - `entry_date` string, date, required
      - `match_tier` string, required
      - `gross` string, required
      - `currency` string, required
      - `amount_differs` boolean
  - `sent_at` string, date-time, nullable
  - `last_sent_to` string, nullable
  - `issued_at` string, date-time, nullable
  - `created_at` string, date-time, required
  - `updated_at` string, date-time, required
  - `lines` ArInvoiceLineOut[]
    - `line_type` 'product' | 'service' | 'text' | 'section' | 'discount'
    - `sort_order` integer, required
    - `group_label` string, nullable
    - `product_id` string, nullable
    - `item_code` string, nullable
    - `description` string, nullable
    - `quantity` string, nullable
    - `unit_price` string, nullable
    - `unit_label` string, nullable
    - `account_code` string, nullable
    - `vat_code_id` string, nullable
    - `line_discount_kind` 'none' | 'percent' | 'amount'
    - `line_discount_value` string
    - `service_period_start` string, date, nullable
    - `service_period_end` string, date, nullable
    - `id` string, required
    - `net_amount` string, required
    - `vat_amount` string, required
    - `gross_amount` string, required

## Other responses

- `422`: Validation Error

---

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