In partnership with Accounting, manage partner and reseller billing activities for TaxConnex services delivered through these relationships, including coordination of billing information, reconciliation, issue resolution, follow-up, and communication with internal teams and partners to support accurate and timely billing. Manage implementation of third-party add-on services, including ECM and tax calculation add-on services for existing sales tax compliance clients, coordinating requirements, set up, testing, client and internal communication, handoff, and readiness for ongoing support.