How to build a fintech app like Revolut

Start with a financial proposition, not a feature clone

Understanding how to build a fintech app like revolut starts with separating the visible app from the financial operation behind it. Customers see balances, cards, transfers, and currency exchange. Behind those screens sit regulated entities, banking relationships, payment schemes, identity checks, fraud controls, ledgers, reconciliation, and customer support.

For MyDiscussions readers planning a competing or adjacent product, the goal should not be feature parity. Revolut’s product breadth reflects years of development and capabilities that vary by market and legal entity. Replicating its interface does not replicate its permissions or economics.

A more defensible starting point is one customer segment, one launch jurisdiction, and one recurring money problem. For example: a multicurrency spending account for frequent travelers, or a payment account for freelancers receiving international income. Those products need different transfer coverage, risk controls, and support processes.

Define what “like Revolut” means for your MVP

Revolut-inspired products commonly combine an account, a card, transfers, currency conversion, and spending insights. Treat that combination as a menu—not a minimum requirement.

Write a product boundary before approaching vendors:

• Customer: resident consumers, sole traders, or incorporated businesses?
• Geography: where are customers resident, and where will they send or spend money?
• Money movement: domestic transfers, international payouts, card purchases, or all three?
• Currencies: which balances can customers actually hold, rather than merely display?
• Revenue: subscriptions, disclosed conversion fees, interchange participation, or business services?
• Service promise: what happens when a card fails or a transfer remains pending?

A practical initial scope

An MVP must reduce product breadth, not financial integrity. Reconciliation, complaints, account restrictions, and recovery from failed payments belong in the first release even if savings vaults and spending charts do not.

Choose the regulatory and partnership model first

Your launch jurisdiction determines which activities require authorization, which can be performed through partners, and what responsibilities remain with your company.

Distinguish a bank deposit from an e-money or payment account. Safeguarding arrangements and deposit protection are not interchangeable. Customer disclosures must describe the actual legal structure, not imply that every Revolut-like account is a bank account.

The FCA’s payment services and electronic money guidance provides a useful official starting point for UK planning. Other markets require their own analysis.

Partner-led launch versus direct authorization

A partner-led model can provide account infrastructure, payment access, or card issuance without your company becoming a bank. Examples worth evaluating, depending on geography and use case, include ClearBank, Banking Circle, Solaris, and Stripe Treasury. These are not interchangeable offerings; availability, eligibility, and permitted responsibilities differ.

Direct authorization may offer more control over product design and partner relationships, but also adds governance, capital, compliance, and supervisory obligations. Authorization alone does not provide access to every payment rail or card scheme.

Before signing, clarify:

• Which legal entity contracts with the customer?
• Who holds or safeguards customer funds?
• Who performs checks, makes risk decisions, and submits required reports?
• Who handles complaints, disputes, and account closures?
• What happens to customers and funds if the partnership ends?

Use specialist counsel to validate the model. A vendor’s API documentation is not evidence that your proposed service is legally permitted.

Select providers around complete money journeys

A provider should be assessed through workflows, not feature checkboxes. Test an inbound transfer, a rejected beneficiary, a duplicate webhook, a partial card reversal, and a customer closure with funds remaining.

Build a weighted vendor scorecard

Evaluate account providers, card platforms such as Marqeta or Adyen Issuing, identity vendors such as Veriff or Entrust Identity Verification, and cross-border platforms such as Wise Platform against concrete criteria:

• Coverage: supported customer types, jurisdictions, currencies, and rails.
• Control: ability to freeze cards, restrict accounts, set limits, and investigate events.
• Data quality: stable transaction identifiers, settlement reports, and event history.
• Reliability: documented retry behavior, incident escalation, and recovery procedures.
• Economics: minimum commitments, per-event charges, reserves, and termination costs.
• Portability: access to records and a workable migration or wind-down process.

Request production-like sandbox scenarios and sample reconciliation files. A polished API can still leave your team manually resolving ambiguous settlement records.

Avoid assuming that two providers create instant redundancy. Moving a customer account or card program between regulated partners is substantially harder than switching an ordinary software API.

Design the ledger before the dashboard

The core engineering challenge is maintaining a trustworthy account of money while external systems deliver delayed, duplicated, or out-of-order events.

Use a double-entry financial model

Every movement should produce balanced ledger entries. Separate:

• Customer liabilities from company revenue and expenses.
• Posted balances from pending holds.
• Available funds from amounts awaiting settlement.
• Each currency’s accounts and precision rules.
• Ledger records from provider observations and imported statements.

Store money in integer minor units or carefully defined fixed-precision decimals—not floating-point values. Currency precision varies, so “multiply everything by 100” is not a universal solution.

An internal transfer between customers can debit one customer liability account and credit another within a single atomic posting operation. An external transfer additionally needs clearing and settlement accounts. Currency conversion requires linked postings across currencies, with explicit rate, fee, and rounding treatment.

Products such as Modern Treasury Ledgers or Formance can support ledger infrastructure. Whether buying or building, retain ownership of the accounting model and verify atomicity, auditability, currency handling, and balance queries.

Model payments as state machines

A transfer may move through created, screened, submitted, pending, completed, rejected, or returned states. A card transaction follows a different lifecycle involving authorization, capture, reversal, clearing, and potentially a dispute.

Use:

• Idempotency keys for money-moving requests.
• Unique provider-event constraints for duplicate detection.
• An inbox pattern for durable webhook processing.
• An outbox pattern for reliable event publication.
• Compensating entries rather than editing posted financial history.

Do not promise “exactly once” execution across every external system. Design for retries and make their effects safe.

Reconcile independently of webhooks

Webhooks tell you what a provider reported at a particular moment. They do not replace reconciliation.

Compare internal postings with processor records, payment reports, and bank statements. Route unmatched items into an operations queue with an owner and aging threshold. Where report timing permits, reconcile at least daily, with more frequent checks for high-risk flows.

Choose a stack your team can operate

Flutter and React Native are credible choices for shared mobile development. Native Swift and Kotlin offer deeper platform integration but require separate implementation effort.

For the backend, Kotlin with Spring Boot, Go, or TypeScript with NestJS can work. Team competence, transactional discipline, and operational maturity matter more than fashion.

A reasonable starting architecture includes:

• PostgreSQL for transactional records and ledger data.
• Redis for caching and rate limiting, never as the authoritative balance store.
• A managed queue for background processing and provider events.
• Temporal, where justified, for durable multistep workflows.
• OpenTelemetry for tracing, with sensitive fields redacted.
• Managed key and secrets services, such as AWS KMS and Secrets Manager.

Prefer a modular monolith initially when it simplifies transactions and deployment. Separate responsibilities clearly so high-volume or independently governed components can be extracted later.

Make security and fraud controls product requirements

A fingerprint prompt does not secure a fintech account by itself. Enrollment, device changes, recovery, beneficiary creation, and support-assisted actions are all attack surfaces.

Use the OWASP Mobile Application Security Verification Standard to structure mobile security requirements and testing. Include secure storage, transport protection, sensitive-data handling, and platform interaction.

Prioritize controls around irreversible actions:

• Step-up authentication for risky transfers and security changes.
• Device binding and suspicious-session detection.
• Transfer limits and new-beneficiary controls.
• Least-privilege administrative access.
• Dual approval for sensitive operational actions.
• Auditable support access and restricted data exports.

For cards, reduce exposure to raw cardholder data through provider-hosted or approved tokenized components. Confirm the remaining obligations using the PCI Security Standards Council’s PCI DSS resources. Outsourcing card processing can reduce scope; it does not automatically remove responsibility.

Fraud policies also need operational capacity. Every hold or review creates a queue. Define who investigates, what evidence is available, and how customers receive appropriate updates without compromising an investigation.

Build the app step by step

1. Validate a specific customer journey

Interview prospective customers about actual money flows, not desired features. Document funding sources, transfer destinations, currency needs, and failure experiences.

Exit criterion: a clear segment, recurring use case, and reason to switch from existing accounts.

2. Confirm legal feasibility and unit economics

Map each activity to the required permission or partner arrangement. Estimate contribution margin after provider fees, payment costs, support, fraud losses, and verification.

Do not treat interchange or subscription revenue as guaranteed. Customer behavior and local rules materially affect both.

Exit criterion: a viable operating model reviewed by qualified specialists.

3. Prove provider workflows

Integrate sandbox account creation, identity checks, transfers, and cards where relevant. Simulate missing events and provider downtime.

Exit criterion: documented ownership and recovery behavior for every critical failure.

4. Implement the ledger and operational tooling

Build posting rules, holds, reconciliation, restrictions, and investigation views before polishing analytics.

Exit criterion: each test transaction can be explained from initiation through final settlement or return.

5. Build the customer-facing experience

Prioritize onboarding clarity, available balance, fees, payment status, card controls, and support access. Explain why a transfer is pending without presenting estimated arrival as guaranteed.

Exit criterion: customers can complete core tasks and understand unresolved transactions.

6. Run a controlled pilot

Launch with limited eligibility, transaction limits, staffed support, and explicit monitoring. Rehearse compromised-account response, reconciliation breaks, provider outages, and service wind-down.

Exit criterion: financial exceptions are understood and resolved within agreed operational targets.

7. Expand one dimension at a time

Add a currency, geography, customer segment, or product—not all four simultaneously. Each changes risk, support, and reconciliation requirements.

Budget for a financial operation, not just app development

A credible estimate depends on jurisdiction, permissions, provider readiness, and scope. A prototype and a production financial service should never share the same budget assumptions.

Separate costs into:

• Setup: legal analysis, integrations, program onboarding, product design, and security assessment.
• Recurring: engineering, compliance, operations, infrastructure, monitoring, and vendor minimums.
• Usage-driven: identity checks, transfers, card production, FX execution, and disputes.
• Funding requirements: reserves, prefunding, regulatory capital where applicable, and liquidity buffers.

Partner approval and contracting can become the critical path even when engineering progresses well. Obtain indicative commercial terms before committing to a launch date.

Common mistakes that undermine Revolut-like apps

Copying breadth before proving demand. A narrow product with reliable payments is stronger than five unfinished financial services.

Treating the provider balance as the entire accounting system. Your business still needs explainable customer liabilities, fees, adjustments, and settlement records.

Allowing customer support to edit balances directly. Use permissioned, auditable adjustment workflows that generate valid ledger postings.

Leaving recovery until later. Lost phones, locked accounts, delayed transfers, and failed identity checks are ordinary product journeys.

Ignoring partner concentration. Maintain exports, escalation paths, and a realistic exit plan.

Measuring only registrations. Track funded activation, successful payments, reconciliation exceptions, fraud outcomes, and support demand. Growth is not healthy if financial breaks grow faster.

For related product-planning frameworks, browse more Build an app like X topics.

Frequently asked questions

Do I need a banking license to build an app like Revolut?

Not necessarily. Some products operate through licensed banking, payment, or e-money partners. Your own authorization requirements depend on the activities, jurisdiction, and contractual structure. A partner relationship does not automatically cover everything your app offers.

How long does development take?

A constrained partner-led launch generally requires months rather than weeks. Authorization, contracting, integration approval, and operational readiness can extend the schedule significantly. Estimate milestones from confirmed dependencies, not screen count.

Should I build or buy the financial ledger?

Buy when a provider meets your accounting, audit, performance, and portability requirements. Build when unusual posting rules or control requirements justify the maintenance burden. Either way, your team must understand and test the financial model.

What should come after the MVP?

Choose expansion based on demonstrated customer behavior and operational readiness. Additional payment coverage, better funding options, or improved support may create more value than investments or lending. Expand only when the existing product’s balances, payments, and exceptions are reliably controlled.