Billing Migration & Technical Specialist

Why Join Us? Onecom is the UK's leading business technology provider, shaping the way we work, connect, communicate and operate. You will join a multi-award-winning company, with over 800 talented people committed to delivering great customer experiences driven by the Onecom Way; Think Kaizen, Be Respectful, Build Relationships, Make it Happen, Work Smart, Be Amazing. About the role We're looking for an experienced Billing Migration & Technical Specialist to play a key role in a major billing platform transformation. Working as the billing Subject Matter Expert (SME), you'll lead the migration of billing processes and logic from our incumbent platform, Tekton, to aBILLity, ensuring accuracy, governance, and a seamless customer experience throughout the transition. This is a highly visible role, working across Finance, Technology, Operations and Product teams to ensure billing integrity, protect revenue, and support successful delivery of a business-critical programme. What you'll be doing Analyse and document existing billing processes, rating structures, discounts, credits and invoicing logic within Tekton. Translate legacy billing logic into future-state requirements and configurations within aBILLity. Support data mapping, cleansing, transformation and migration readiness activities. Lead billing validation, reconciliation, parallel-run testing and user acceptance testing. Identify migration risks, billing gaps and process improvements, driving issues through to resolu