Onboarding 600+ retailers to Stax taught me more about fintech than any conference, consultancy or case study ever did. I've been in this game long enough to know that fintech isn't only about the tech. It's about really understanding what happens in the real world when you connect lenders to retailers. When you've processed over £700m across 220,000 loan applications in three years from a standing start, there's no hiding place. Everything gets exposed. I want to share what I've actually learned from getting 600+ retailers live and transacting on the Stax platform.
The Onboarding Journey Isn't Linear
When a retailer signs up, people assume it's just paperwork. It's not. The actual process is deliberate and structured because it needs to be. We start with due diligence on the retailer itself. Credit checks. Financial assessment. Understanding their business model, their customer base, their compliance footprint. This matters enormously because we're connecting them to lenders. Everyone needs to trust everyone else. Then comes file collation. Contracts, certifications, proof of customer demand, historical sales data. Sounds dull. It's actually critical because you can't set up lender relationships without proper due diligence. Then we configure their lender connections. At Stax, we work across a waterfall of 5 to 6 lenders. This isn't for show. It means every retailer has a choice of credit options from multiple sources, enabling them to build the best credit strategy possible. But building a platform that handles the complexities and nuances of a retailers individual strategy, then setting that up for each retailer is intricate work. The rate cards come next. This is where it gets even more complex.
Rate Cards Are Where Theory Meets Reality
Rate Cards are what we refer to internally and dictate the credit strategy for each retailer. This is the friction point nobody talks about but everyone feels. Let me give you a real example. One renewables retailer we onboarded sells across seven different product verticals: heat pumps, solar PV, battery storage, boilers, and various combinations. Each vertical has different price points, different customer demographics, different risk profiles. Now multiply that by the four lenders the retailer has in place. Each lender offers different product types:
- Buy Now Pay Later with deferred periods of 3, 6, 9, or 12 months
- Interest Free Credit
- Interest Bearing Credit at 9.9% or 13.9% APR
- Terms ranging from 12 months to 180 months Then add waterfall positioning. Which lender gets first crack at second-line customers? Which gets prime customers first? Which is the fallback? For this one retailer, the rate card configuration runs to dozens of rows. Seven product verticals. Four lenders. Three product types. Multiple term lengths. Different subsidy rates. Different APRs. Different waterfall positions depending on customer credit profile. Now imagine getting that wrong. One conflict in the waterfall decisioning and customers get error messages. One misconfigured rate and the retailer's margins collapse on a product line if the wrong finance product is utilised. You can't automate away the responsibility of constructing a credit strategy. If you do, something breaks. The whole process from first conversation to the retailer going live and transacting takes between 2 to 4 weeks. That seems reasonable until you realise how much precision work happens in those weeks.
What Actually Determines Success
The most unexpected lesson came down to people, not systems. It's not the technology. It's not the slickness of the onboarding portal or the elegance of the API. Success comes down to whether the people at the top of the retailer actually believe in consumer credit. You can have a perfect product. You can have the right lenders. The rate cards can be flawlessly configured. But if the managing director or finance director isn't genuinely bought in on the benefits of offering credit to their customers, then the sales team won't push it. The customer-facing staff won't offer it. The whole thing underperforms. We learned this the expensive way. We use Salesforce Experience Cloud as our retailer frontend. Every retailer user needs a licence. When we onboard a retailer with 50 staff, that's 50 licences. But if management enthusiasm wanes after three months, those licences sit unused. The staff don't log in. The platform gathers dust. Our BDM and Account Management teams work hard to prevent this. They build relationships, track usage, re-engage retailers who go quiet. But it still happens. Management gets distracted. Priorities shift. Suddenly we're paying for 50 licences that nobody's using. That's not just a waste. It directly impacts our cost of acquisition. Every dormant licence is money spent acquiring a retailer who isn't transacting. This changed how we approach these relationships entirely. We don't just sell a platform. We have to help retailer leadership understand the opportunity. When we do, everything else follows.
Speed at Scale Has Real Constraints
You might think that after 600+ retailers, we'd be turning these around in days. We've have got better. But we still see friction because fintech has legitimate guardrails. As the embedded finance market in the UK continues its growth trajectory, hitting £26.09 billion in 2025, there's genuine demand for what we do. But demand doesn't remove the need for proper due diligence or credit strategy thinking. The retailers joining the platform increasingly want sophistication. They don't just want another payment option. They want to understand their customer financing better. They want to optimise acceptance rates. They want proper reporting. That's a good thing. It raises the bar. But it also means you can't commoditise onboarding in ways you might with a simpler product.
What We Got Right
We invested heavily in people. Our internal team is genuinely excellent because this work demands it. You're managing relationships between retailers, lenders, regulators, and customers. That's not a job for a process alone. We also systemised the parts that could be systemised while preserving human judgment where it matters most. The configuration tools are far better than they were. The training is more structured. The documentation is comprehensive. And we stayed true to waterfall decisioning even as it made onboarding harder. It would have been easier to pick one lender and be done with it. But that would have been wrong for customers. Retailers now know their customers get the best available credit offer. That builds trust.
The Retailer Finance Opportunity Remains Enormous
When I look at UK point of sale finance, we're talking about £13.1bn in outstanding lending as of 2023. The market continues to expand. Home improvement and renewables are still growing sectors as consumers invest in their homes and as the green agenda drives demand. But scale isn't inevitable. You don't get there through slickness or speed alone. You get there by:
- Understanding the actual operational constraints of retailers
- Being genuinely disciplined about credit strategy and lender management
- Building trust with the people making decisions at retailer level
- Being honest about what's genuinely complex and refusing to paper over it
What I'd Tell Someone Starting This Today
If I was building this from scratch again, I wouldn't change the fundamentals. I'd invest even more upfront in understanding each retailer's business. I'd spend more time with their leadership before any system configuration happened. I'd get the rate card conversations right before we tried to move fast. The 2 to 4 weeks per retailer feels long until you realise it's actually the time required to do it properly. The complexity of waterfall decisioning and rate card management feels like a burden until you remember that your job is to serve retailers and their customers well. That work shouldn't be fast. It should be rigorous. Six hundred retailers. Seven hundred million pounds. Two hundred and twenty thousand loan applications. Three years from a standing start. That's not luck. That's what happens when you take the fundamentals seriously.
Sources
- Custify. (2025). SaaS Customer Onboarding and Retention Statistics
- ProductLed. (2025). State of B2B SaaS in 2025 (Analysis of 446 Companies)
- Cloud Coach. (2025). 51 Statistics You Need to Know: The State of SaaS Onboarding and Implementation
- GlobeNewswire. (2024). UK Point of Sale Finance (including Buy Now Pay Later) Market Insight Report
- ResearchAndMarkets. (2025). United Kingdom Embedded Finance Business Report 2025-2030
- Novuna. (2024). Providing Finance Across Key Retail Finance Sectors
- Solar Power Portal. (2024). Government, GFI Launch Green Home Finance Strategic Partnership