Partner-initiated "money-in": charges the cardholder card in the path and credits the given Accounting-API account. The funding source is resolved by the platform from that card (the cardholder's highest-priority active payment method); partners neither see nor supply one. Idempotent via the Idempotency-Key header (per card, per day): a retry replays the original charge with its original status and an Idempotent-Replayed: true response header, so a replay is told apart from a fresh create by that header rather than by the status. The account_uuid must be an active Accounting-API account of a Business Partner this partner is entitled to, so charging onboarding also requires an accounting_api entitlement. Charging itself is entitled separately from the rest of the Distributor API: a partner without a distributor_charging role is refused (403), so charging can be withheld per distributor.