On 8 October, we’re bringing together an FCA-authorised EMI and our own strategy and implementation leads to talk through two questions: how do fintechs build card programmes for complex corporate clients? And, crucially, which parts are worth building themselves? This article sets up that conversation, the shift that creates the problem, the parts of the stack it touches, and the build-or-leverage decision every scaling fintech has to face sooner or later.
Growth in fintech typically means moving upmarket. A product that started out serving freelancers and small businesses starts attracting larger, more complicated customers. Then at some point the pitch decks begin to mention “enterprise.” It is a good problem to have, but it is also the point where the demands on a card programme change completely.
Serving a sole trader and serving a multinational are not the same job scaled up. Let’s imagine an EMI onboarding a corporate group with subsidiaries in five countries, spending in several currencies, with a finance team that expects real control over who can spend what, where, and up to how much. Everything that was simple at the small end now has to work across multiple entities, currencies, and approval layers at once. Being able to do exactly that is what separates the fintechs that can genuinely serve complex corporate clients from those who can’t.
What Makes Corporate Card Programmes Complex
The complexity arrives from a few directions at the same time.
The first is corporate structure. A single client may be a parent company with several subsidiaries, each needing its own accounts, cards, and reporting. The group, at the same time, wants one consolidated view across all of them. If a card programme has been built around a flat, single-entity customer, it will struggle the moment that hierarchy appears.
Currency is the second. A business trading across borders wants to hold and spend in the currencies it operates in, and to avoid a conversion cost on every transaction. That means multi-currency accounts and cards, not a single base currency with everything converted on the way out.
Finally, there is the question of control, and it grows with client size. A larger finance team expects granular permissions, spending rules by team or category, approval steps for larger purchases, and clean transaction data flowing straight into its own accounting and reporting systems. What a small customer never asks for often becomes a deal-breaker for a big one.
Together, and at volume, these issues are serious engineering and compliance undertakings.
The Operational Reality of Onboarding a Complex Client
There is also the part that happens before a single card is issued. Onboarding a multinational client is a different exercise from onboarding a small business. Know Your Business checks have to cover a whole corporate structure: layers of ownership, directors, and beneficial owners across jurisdictions, each with its own documentation and its own regulatory expectations.
At this point a lot of programmes stall. The card mechanics might be ready, but the onboarding and compliance workflows aren’t built to handle a group structure. As a result, every complex client becomes a manual, weeks-long project. Serving this segment at scale means the operational side – onboarding, verification, and the add-ons that complex clients expect – has to be as robust as the card issuing itself.
The Parts of the Stack You Have to Get Right
Behind a corporate card programme sits a stack most customers never see, and getting each layer right is what turns a demo into a product an enterprise will trust.
There is the licensing and BIN sponsorship that allows cards to be issued at all. There is the API layer that lets a fintech create, configure, freeze, and manage cards programmatically instead of by hand. There are the corporate controls: limits per card, per transaction, and per period, merchant and category restrictions, roles and approvals. There are the multi-currency workflows that let money be held and spent across markets.
Underneath all of it runs compliance that never stops, KYC, KYB, and AML on every cardholder, plus scheme rules and security standards that change every year.
Each of these is a project in itself, and each has to keep working, and keep pace with regulation, as the programme grows.
Build, or Use What Already Exists?
This is the decision every scaling fintech eventually reaches. The question is which of those layers to build and own, and which to leverage from a provider who has already built them.
The honest test is whether a given layer is where the fintech competes. The credit or product decision, the customer relationship, the experience of using the product, those are worth owning, because they are what set one provider apart from another. But card-issuing plumbing, BIN sponsorship, scheme certification, and the compliance machine underneath are not where customers are won or lost, and every engineering hour spent maintaining them is an hour not spent on the product.
Time-to-market cost plays a role as well. Building the full issuing and compliance layer in-house is measured in years and licences, not weeks and sprints. For most fintechs it only makes sense at a very large scale. Even then, it rarely pays for itself against the alternative of building on infrastructure that already exists.
Serving a Complex Niche Without Owning the Whole Stack
This is where white-label infrastructure fits. It lets a fintech put a fully branded, compliant card programme in front of complex corporate clients while a provider carries the licensing, the card-network connections, the multi-currency rails, and the ongoing compliance beneath it.
The aim is to keep building the part that matters, the niche a fintech understands better than anyone, while standing on infrastructure already proven at scale. A provider serving a specific, complicated corner of the B2B market can then move quickly and stay compliant, without turning itself into an infrastructure company on the side.
What the Webinar Covers
That is the strategic case. The harder question is how it actually gets implemented, and that is what our next webinar is built around.
On 8 October 2026 at 6pm EEST, Wallester is hosting a live White-Label webinar, “Building for the Complex: How EMIs Scale Corporate Card Programmes With White-Label Infrastructure.” In 40 minutes (30 minutes of discussion, 10 of live Q&A), the panel moves from the business case through to the technical build:
- Alexey Reshko, COO of Transferra, an FCA-authorised EMI, on the operational realities of onboarding multinational corporate clients and building scalable B2B growth on white-label infrastructure.
- Karine Martinez, Head of Strategic Partnerships at Wallester, on time-to-market, navigating BIN sponsorship, and serving complex B2B niches.
- Georgi Prelovski, Senior Implementation Manager at Wallester, on the backend: integrating the API suite, setting up corporate controls, and managing multi-currency workflows.
- Angelina Prokopenko, Marketing Project Management Team Lead at Wallester, moderating and leading the Q&A.
If scaling into more complex corporate clients is on your roadmap, this is the practical next step. Places are limited; >>>RESERVE YOURS HERE.
