Principal Technical Account Manager, Merchants

About the Role We're looking for a Senior / Principal Technical Account Manager to own the post-sales relationship for our largest enterprise merchant customers. You will own the customer relationship, the commercial trajectory, and the connective tissue between the customer and every BT function for our most strategic, high-value accounts. These are sophisticated, high-volume merchants running mission-critical payments on our platform, with complex stacks, multiple stakeholders, and executive sponsors. This is a senior, customer-facing role for someone who knows payments deeply enough to be a credible strategic advisor to a merchant's payments, engineering, and finance leadership. This is an opportunity to set the standard for how we run enterprise post-sales as our TAM function scales. What You'll Do Own the Relationship Be the named Basis Theory owner for a focused book of our largest enterprise merchant accounts, from the late-deal handover onward Build and maintain executive relationships across payments, engineering, product, and finance Act as a strategic advisor on payments strategy, design, and delivery at scale: orchestration, cost and authorization optimization, resiliency, and roadmap Retention & Renewals Own GRR + NRR for a high-value book where a single account can move the number Run complex, multi-stakeholder, often multi-year renewal cycles: review usage and the value delivered, surface risk early, and equip the sales team to scope and land renewal terms Monitor for the early signals of a drifting relationship (usage dips, quieter channels, sponsor changes, competitive noise) and act before they become churn Expansion Identify, scope, and warm up expansion across a large, complex footprint: more volume, new product surfaces, new regions, and new use cases Pass qualified commercial upsell and cross-sell opportunities to sales to close, staying close given the size and complexity of enterprise deals Business Reviews & Customer Health Run executive business reviews for your accounts, designing the agenda, the narrative, and the follow-up while the FDE owns the technical content Maintain a current, board-ready picture of health across your book: utilisation against contracted value, escalation status, sponsor strength, and multi-threaded relationships Lead internal coordination when a strategic account needs something by pulling in the right function, mobilizing senior stakeholders, and owning the thread through resolution Required Experience 10+ years in technical account management, strategic customer success, or enterprise post-sales account management, ideally in payments, fintech, or API/infrastructure A track record of owning renewals and expansion for large, complex enterprise accounts, or carrying a meaningful NRR / retention number Executive presence: credible and composed with VP/C-level stakeholders, and able to build multi-threaded senior relationships Credible with technical stakeholders: you can talk to a merchant's engineering or product team about their payment stack without an engineer in the room Solid understanding of the card lifecycle (authorization, capture, settlement, refund, chargeback) and where tokenization and vaulting fit Familiarity with enterprise merchant payments concerns: payment orchestration, multi-PSP routing, network tokens, authorization-rate and cost optimization Ability to turn usage data into a value and expansion narrative for a senior audience Why Basis Theory Basis Theory is at an inflection point. We've got a growing enterprise customer base, fresh funding, and a unique position at the intersection of payments infrastructure and agentic commerce. You'll work with great people on genuinely hard problems with the most demanding customers in payments, and shape how enterprise post-sales takes form as we grow.