This is the billed call. Each XML costs $0.20 MXN, charged once per CFDI.Takes UUIDs that are currently in the metadata stage — typically ones you found via a preview and GET /invoices/sat?sync_state=metadata — and queues their XML download.Cost confirmation. The server always recomputes the cost; confirm_cost_mxn is only ever checked against it, never trusted. Send it and a mismatch returns 409 rather than charging a different amount than you were shown. Omit it and the call is allowed only up to 100 invoices; past that confirmation is required, so a large import cannot happen by accident.Anything not importable is reported in skipped with a reason rather than failing the call: not_found, wrong_team, already_imported, already_queued, is_nomina (nómina XMLs carry employee PII and are never downloadable), not_importable.