This Catalyst project completes the Wholesale Broadband as a Service vision by standardising and automating service assurance interactions between Network Providers (NetCos) and Service Providers (ServCos). Building on the success of earlier phases that focused on wholesale broadband ordering, Phase III addresses the critical in‑life operational layer: fault, outage, service quality, and service test management. The project delivers a digitised, API‑driven, and globally reusable service assurance framework, aligned with TM Forum’s Open Digital Architecture (ODA) and Open APIs. By defining consistent, standardised interactions for wholesale broadband assurance, CSPs can significantly reduce design and integration effort, accelerate implementation, and lower operational costs. Vendors benefit from reduced development complexity and easier interoperability, while end customers experience faster fault resolution and improved service quality. Focusing on real‑world wholesale broadband use cases, the solution enables CSPs to operate faster, cheaper, and more effectively—unlocking new business opportunities and delivering a better overall customer experience through improved service assurance performance.