Fintech · App development
Fintech app development for payments, wallets, lending and personal finance
We build fintech and finance apps where correctness is the feature: double-entry ledgers, idempotent payment flows, KYC onboarding and audit trails, wrapped in mobile and web experiences customers trust with their money.
Short answer
Fintech app development is building mobile and web products that move, store or manage money, such as wallets, payment apps, card programmes, lending platforms and budgeting tools, on top of regulated partners like banks, card issuers and payment processors. Innovation Insight builds fintech MVPs from $40k to $80k in three to five months, with KYC, ledgers, payment integrations and the security controls auditors and banking partners expect.
Reviewed by Zain Khalid Malik, CTO & Co-founder · Updated
Fintech apps we build
| App type | Core features | Typical partners |
|---|---|---|
| Digital wallet and payments | Balances, P2P transfers, top-ups, card payments, QR payments | Stripe, Adyen, Checkout.com, Marqeta, local payment rails |
| Neobank and banking-as-a-service front end | Accounts, cards, statements, spending insights | Unit, Treasury Prime, Swan, Solaris, Railsr |
| Lending | Applications, credit decisioning, repayment schedules, collections | Plaid, credit bureaus, open banking providers |
| Personal finance and budgeting | Account aggregation, categorisation, goals, alerts | Plaid, TrueLayer, Tink, MX |
| Investing and savings | Portfolios, recurring buys, statements, tax documents | Alpaca, DriveWealth, brokerage APIs |
| B2B payments and invoicing | Invoices, approvals, payouts, reconciliation with accounting | Stripe Connect, Wise, QuickBooks, Xero |
Card issuing, payments and payouts
Three money flows come up in almost every fintech brief, and each has its own partner model. Accepting payments runs through a gateway or processor such as Stripe, Adyen or Checkout.com; our payment gateway integration page covers that work. Paying people out, to sellers, drivers, guides or agencies, usually means Stripe Connect or a payouts API, which handles the identity checks on the recipient; that is what we built for TamTracker and LogFish. Issuing cards means a card programme: either a bundled one such as Stripe Issuing, which brings its own bank partner, or an issuer-processor such as Marqeta or Lithic plus a sponsor bank of your own. Your app then creates virtual or physical cards, sets spend controls and approves or declines each authorisation in real time through a webhook. The processor talks to the card network and the bank holds the funds.
- Choose the card programme for your markets first; its approval usually sets the launch date, not the build.
- Design the ledger so every authorisation, capture, refund and reversal maps to an entry, and reconcile daily against the processor's reports.
- Build the real-time authorisation webhook with a strict time budget and a safe default for when your service is slow.
- Cover the card lifecycle: issue, activate, freeze, replace, spend controls, disputes and statements.
- Prepare the compliance evidence the programme asks for (KYC records, sanctions screening, audit logs) as part of the build, not after it.
Finance app or fintech app?
A fintech app moves money: payments, wallets, lending, payouts and cards. A finance app mostly reads and organises it: budgeting, expense tracking, reporting and investment dashboards built on open-banking data. Buyers use finance app development, financial app development and fintech app development for both, but the distinction matters: a read-only finance app has a much lighter partner and compliance footprint than a wallet, and that shapes both the cost and the timeline.
What we have built with money in it
- TamTracker: Stripe subscriptions, an agency partner portal and Stripe Connect payouts with revenue tracking.
- LogFish: Stripe payments and payouts to guides alongside Apple and Google subscriptions, in one React Native app.
- Paint Nite: a three-step ticketing checkout with idempotent Stripe payments, rebuilt beside the legacy system.
- Edge OCR: a multi-tenant platform with usage-based billing.
- Seek My Service: a credit-based vendor economy in a two-sided marketplace.
None of these is a bank. Our fintech work to date is payments, payouts, billing and marketplace economics inside larger products; the ledger, reconciliation and compliance patterns below are how we approach wallets, lending and card programmes.
The engineering that makes a fintech app trustworthy
- A double-entry ledger as the source of truth for balances, so money is never created or lost by a bug or a retry.
- Idempotent APIs and webhook handling, so a network timeout never charges a customer twice.
- Daily reconciliation between your ledger and every partner's reports, with alerts on any mismatch.
- KYC and KYB onboarding through providers such as Onfido, Persona, Sumsub or Alloy, with manual review queues.
- PCI DSS scope kept small by tokenising card data with your processor, so card numbers never touch your servers.
- Immutable audit trails, role-based access, multi-factor authentication and device binding for sensitive actions.
- Fraud signals and velocity limits on transfers, with rules your operations team can adjust.
Security and compliance
We design for the frameworks your partners and auditors will ask about: PCI DSS for card data, SOC 2 controls for access, change management and logging, GDPR for EU customers, and the data-handling rules in your banking partner's programme agreement. Mobile apps get certificate pinning, jailbreak and root detection, biometric re-authentication for payments, and secure storage for tokens. Every release goes through automated security scanning and a manual review of money-moving code paths. See our security page for how we run delivery.
What it costs
Fintech app development costs $40k to $80k for an MVP with one product, one payment partner, KYC and a ledger, delivered in three to five months, and $80k to $180k for a full platform across iOS, Android and web with several partners, reconciliation and fraud rules, over five to nine months. Partner fees are extra.
| Scope | What is included | Range | Timeline |
|---|---|---|---|
| Fintech MVP | One product (wallet, lending or budgeting), KYC, one payment partner, ledger, admin console | $40k to $80k | 3 to 5 months |
| Full fintech platform | iOS, Android and web, several partners, reconciliation, fraud rules, reporting | $80k to $180k | 5 to 9 months |
| Dedicated fintech team | Engineers, QA and DevOps working on your roadmap | From $4,000 per engineer per month | Monthly |
Partner fees for banking, KYC and payments are separate and usually charged per account or transaction. We help you model them during discovery so your unit economics are clear before launch.
How we deliver
- Discovery (2 to 3 weeks): product and regulatory model, partner shortlist, money flows, ledger design, fixed estimate.
- Design: onboarding and payment flows tested with users, because trust is won or lost in the first five screens.
- Build: two-week sprints with automated tests on every money-moving path and sandbox testing against each partner.
- Certification and launch: partner reviews, security testing, app store approval, staged rollout with limits.
- Operate: reconciliation monitoring, partner API changes, new features under a retainer or dedicated team.
For wider fintech systems, including back-office, reporting and reconciliation tooling, see our fintech software development page.
Sources and further reading
Next step
Tell us what you're building and get a written estimate.
A senior engineer replies within one business day. NDA on request.
Products we've shipped, and what happened next.
Case studies written from the technical documentation of each project: the stack, the scale and the outcome.
Questions we get asked a lot.
Do we need a banking licence to launch a fintech app?
Most fintech apps do not need a banking licence, because they partner with a licensed bank, e-money institution or payment processor that holds the licence. We help you understand what each partner model allows, but you should confirm regulatory questions with a lawyer in your market.
How do you keep us out of PCI DSS scope?
You stay out of most PCI DSS scope by using your processor's hosted fields or SDKs, so card numbers go straight to the processor and your systems only store tokens. That setup typically reduces your obligation to the simplest self-assessment questionnaire.
Which KYC provider should we use?
It depends on your markets and customer types. Onfido, Persona, Sumsub and Alloy all work well; we compare coverage, pass rates and pricing for your countries during discovery.
Can you build for both the US and Europe?
Yes, we design for US partner-bank and card-issuer programmes and for EU open banking and PSD2 providers, and we handle GDPR data mapping for EU customers.
Native or cross-platform for a fintech app?
Flutter and React Native both meet fintech security needs when configured properly and cut cost by sharing one codebase. We go native when an app depends heavily on platform wallets or device security features.
How long does a fintech MVP take?
Three to five months is typical. Partner onboarding and approval often sets the pace more than development does, so we start those conversations in week one.
How do I build a fintech app that includes card issuing?
Pick an issuer-processor and sponsor bank first, for example Stripe Issuing, Marqeta or Lithic in the US, because their programme approval sets the timeline. Then build the ledger, the real-time authorisation webhook, the card lifecycle and spend controls, and the compliance evidence the programme asks for. Expect the programme review to take about as long as the build, so we start it during discovery.
Can you build a finance app that only reads bank data?
Yes, and it is the lighter path: budgeting, expense and reporting apps built on Plaid, TrueLayer or Tink data do not move money, so they run under the aggregator's regulated access rather than a licence of your own, and partner fees and compliance scope stay small. Most of the work is categorisation, deduplication and keeping bank connections alive.
Which payment gateway should a fintech app use?
Most fintech apps should start with Stripe for speed and the widest tooling, move to Adyen or Checkout.com when volumes and markets grow, and add a local acquirer where card costs or regulation demand it. Our payment gateway integration page describes the integration work in detail.