Record a refund

Book a full or partial refund against a tracked entity's ledger and return updated nexus status. The ledger is append-only: a refund is a new row carrying a negative amount, never an edit of the original sale. Pass POSITIVE refund_amount / tax_refunded — the service applies the sign.

Supply refunded_ref (the external_ref of the original sale) wherever you can: the refund then inherits that sale's state, exempt, marketplace and jurisdiction fields so report totals net against the right buckets, and cumulative refunds are capped at the original sale amount (422 refund_exceeds_sale).

state is optional when refunded_ref resolves to a recorded sale — the original supplies it. Provide one or the other: a refunded_ref matching no sale, with no state, is rejected (422 unknown_refund_state) rather than guessed at.

Refunds reduce the dollar totals that economic-nexus thresholds are measured on, but do NOT reduce the transaction count — a refund is not an additional sale. Supports idempotency via idempotency_key.