Think Build Implement Repeat
London, UK +44 7367 067226
WhatsApp FOLLOW f in X
  1. Home
  2. Blog
  3. How Do We Move to a New Payments or Banking Provider Without Breaking Things for Customers?
Problems We Solve

How Do We Move to a New Payments or Banking Provider Without Breaking Things for Customers?

Fintech startups switching BaaS or payments provider must move accounts, cards and flows. We build the integration and a staged cutover with parallel checks.

Updated 3 min readBy SpiderHunts Technologies

Free estimateNo obligation

Get a free estimate

Tell us what you need. A senior engineer reads every enquiry.

Takes under a minute. We never share your details.

  • Free consultation
  • No commitment
  • NDA on request

Prefer to talk? Book a free 30-minute call →

Quick answer — TL;DR

A provider switch goes wrong when the old provider's quirks are baked into your code and there is no way to run both side by side. We put a provider-neutral layer in your product, build the new provider's adapter against it, and plan a staged move of customers in cohorts with reconciliation between old and new at each step.

The decision has been made, now the hard part

Maybe your current provider is changing its terms, winding down a product, or cannot support a feature you need. Maybe a new partner offers something you cannot get today. The commercial side is signed. Now engineering has to move accounts, payment flows, perhaps cards, and all the customer data that goes with them, while customers keep using the app.

The first technical look is not encouraging. The old provider's field names are in your database tables. Its statuses are used in your app screens. Its reference format is assumed in the reconciliation spreadsheet. Its webhooks drive half your notifications.

Where the difficulty really is

Moving data is the visible task. The harder parts are the assumptions nobody wrote down.

  • Your internal model is really the old provider's model with your names on it.
  • The two providers do not have the same statuses, so a straight mapping loses meaning.
  • Some customers have in-flight payments, scheduled payments or standing instructions at the moment of cutover.
  • Account details or card numbers may change, which affects the customer and anyone who pays them.
  • Reconciliation, reporting and support tools all read the old provider's data.

What a rough migration costs

A big-bang switch that goes wrong hits every customer at once: failed payments, wrong balances, cards that do not work. Support is overwhelmed. Your old and new partners both want to know what happened. Even a migration that mostly works leaves a long tail of odd cases that ops clean up for months.

The contractual and regulatory side of moving customers between providers is for your team, your partners and your advisers. Our part is the engineering and the operational tooling around it.

A staged move we plan and build

What we build lets both providers run at once, so customers can move in small groups and each step can be checked.

  1. We map every place the old provider touches: calls, webhooks, stored fields, reports, and support and ops tools.
  2. We introduce a provider-neutral layer in your product with your own statuses and references, and move the old provider behind it first, so nothing changes for customers yet.
  3. We build the new provider's adapter against the same layer and test it in the new provider's sandbox with your real flows.
  4. Each customer gets a provider flag, so the product knows which provider to use for them.
  5. Customers move in cohorts, starting with internal staff accounts, then small groups, with in-flight payments allowed to finish on the old provider.
  6. A reconciliation runs across both providers for every cohort, so balances and payments are checked before the next group moves.
  7. Ops and support tools read through the layer, so they work for both providers throughout.
StageWho is on the new providerWhat we check
Wrap the old providerNobodyBehaviour unchanged, all tests pass
Staff accountsYour own teamEvery flow end to end
First small cohortA group you chooseBalances, payments, notifications, support tools
Larger cohortsGrowing groupsReconciliation clean before each step
Wind downEveryoneOld provider balances cleared and reconciled

How the move feels from the inside

Customers move quietly in batches. Each batch has a clear go or wait decision based on the reconciliation. Support sees which provider a customer is on and gets tailored reply templates for the few changes customers notice, such as new account details.

When the last cohort is across, the provider-neutral layer stays. Adding a second partner later, or moving again, is a much smaller job.

Is this where you are?

  • You are moving provider or seriously considering it.
  • The current provider's names and statuses appear throughout your code.
  • Nobody is sure how in-flight payments will be handled at cutover.
  • Your ops and support tools read directly from the old provider.
  • The plan so far is a single switch-over weekend.

FAQ

Frequently asked questions

The questions readers ask us after this guide.

Still have a question?

Ask us directly — a senior engineer will get back to you.

Ask about your project

Can you advise on the contract or regulatory side of the move?

No. That is for your team, your partners and your advisers. We handle the engineering and operational tooling.

Do we have to move all customers at once?

No. The whole point of the approach is to move them in cohorts with checks between each step.

What about customers whose account details change?

We build the notifications and support templates for that, and the wording is yours to approve.

Can our own engineers do this with you?

Yes. Many teams prefer that. We can lead the layer and adapter design and work alongside your engineers on the rest.

What drives the cost?

How deeply the old provider is embedded, the number of products moving, such as accounts, cards and payments, and how much ops tooling needs to change.

Keep reading

More on Problems We Solve

Start here

Tell us where your fintech ops team loses the day

Describe the queue or the report that eats your ops team's week, the providers and partner bank you sit on, and the admin tools people use now. We will tell you what we would build, what we would leave to your own engineers, and if a setting in your provider's dashboard already solves it, we will say so instead.

  1. You tell us what you needTwo minutes on the form, or a message on WhatsApp.
  2. A senior engineer reviews itAnd comes back with questions, a realistic range and an honest view on fit.
  3. Free 30-minute scoping callWe talk through scope, options and a realistic estimate — with no obligation.
Free estimateNo obligation

Talk to someone who builds this

Send a short brief and we will come back with an honest view and a realistic range.

Takes under a minute. We never share your details.

  • Free consultation
  • No commitment
  • NDA on request

Prefer to talk? Book a free 30-minute call →