---
id: adc-002
title: "FX deltas on customer wires booked to 766 / 666, invoices never adjusted"
status: Accepted
decided: 2026-07-18
effective_from: 2026-01-01
effective_until: null
supersedes: null
superseded_by: null
---

# adc-002 — FX deltas on customer wires → 766 / 666

> **Accepted as formalization** — the method was applied in the 2026-07-11
> books regularization (PRD [compliance › ADC seed table](https://gitea.arcodange.lab/arcodange-org/factory/src/branch/main/vibe/PRD/ai-back-office/compliance.md#accounting-decision-records-adc)).
> Effective from the exercice start (ADC rule 1: effective dates sit on
> exercice boundaries where possible). Operator sanity read = erp#54 human gate.

## Context

KissMetrics pays in USD via Wise; the EUR amounts settled differ from the EUR
invoice totals. Observed deltas: +1.08 EUR on FAC004 and +50.05 EUR on FAC006
(erp#57). The 2026-07-11 regularization forced the choice of where the delta
lives.

## Decision

The customer payment is recorded at the invoice's **remaining EUR amount**
(full-remaining), so the invoice closes exactly. The difference against the
EUR actually received is booked **separately**: gain → account 766 (gains de
change), loss → account 666 (pertes de change). A validated invoice is never
adjusted for FX.

## Base légale & doctrine

- PCG chart — account 666 *pertes de change* / account 766 *gains de change*
  (charges et produits financiers).
- Inaltérabilité of validated entries (Code de commerce L.123-22; PRD
  compliance.md § The ledger grammar): corrections are new documents, never
  edits — the separate 766/666 entry is the append-shaped correction.

## Alternatives rejected

- **Adjusting the invoice amount to the settled EUR** — violates the ledger
  grammar (a validated document is immutable) and inaltérabilité.
- **USD multicurrency invoicing** — open question, not rejected: it is the
  subject of adc-006 (erp#53). If Accepted, adc-006 would supersede or narrow
  this record's scope for future invoices.

## Consequences

- Accounts touched: 766, 766-side produits / 666-side charges financiers.
- Downstream rule: `fiscal.yaml` `fx-deltas-766-666`.
- Annexe: FX-treatment method disclosed from this record at close.
- Interaction: pending adc-006 (retainer currency) may change where FX lives
  for future invoices; until then this method applies unchanged.

## QA & validation

- Applied in the 2026-07-11 regularization; rehearsed on the sandbox (replay
  pack preserved under
  `.claude/skills/dolibarr-sandbox-write/replay-packs/2026-07-11-books-regularization/`).
- The two écart entries themselves are [HUMAN] UI work tracked in erp#57.
- Expert-comptable review: pending (rides the compliance.md § Questions list).

## References

- PRD compliance.md § ADC seed table (adc-002) + § The ledger grammar.
- erp#57 (écarts +1.08 FAC004 / +50.05 FAC006), erp#53 / adc-006.
- `fiscal.yaml` rule `fx-deltas-766-666`.
