Custom financial app development
Managing money, investing, paying or invoicing — financial apps touch on what users consider most confidential. A custom-built financial app combines ease of use with the strict security and compliance the sector demands, tailored to your specific business model and target audience.
We design and develop financial applications for both business and consumer markets: from budgeting and expense tracking to payment platforms, investment apps and mobile accounting solutions.
What is a financial app?
A financial app is a mobile or web application that allows users to manage their financial affairs digitally. The category is broad: from personal budgeting apps that visualise income and expenditure, to business payment platforms processing thousands of transactions per second.
Financial apps include, among others: budgeting and cash flow apps, investment and trading platforms, payment applications and digital wallets, accounting and invoicing software, expense tracking for businesses, pension and wealth management apps, and insurance applications with claims handling.
What these apps have in common is that they handle sensitive financial data, are subject to strict regulation, and must deliver a flawless user experience. A failed transaction or a security vulnerability has direct financial consequences — the tolerance for error is zero.
Why a custom financial app?
Standard fintech solutions offer a starting point, but organisations with specific compliance requirements, unique business logic or integration needs quickly run into the limits of off-the-shelf software. A custom solution gives you full control over the architecture, the data flows and the user experience.
With a custom-built financial app, you decide how transactions are processed, which regulations are implemented (PSD2, PCI-DSS, GDPR), and how the app integrates with your existing systems — from core banking to accounting software. You are not dependent on a third party's roadmap.
Custom development also offers the opportunity to create a distinctive user experience. In a market where users compare dozens of financial apps, the quality of the interface and the speed of interactions make the difference between daily use and deletion after the first session.
Types of financial apps we develop
From personal finance to enterprise payment infrastructure — we build financial apps for a wide range of markets and use cases.
Budgeting and cash flow
Apps that give users insight into their income, spending and savings habits. With automatic categorisation of transactions, budget limits with notifications, and cash flow forecasts based on recurring payments. For both private individuals and SME business owners.
Investment platforms
Trading and investment apps with real-time price data, portfolio management and order execution. From robo-advisors that invest automatically based on risk profile, to full-featured trading platforms with advanced charting and multi-asset support.
Payment and wallet apps
Digital wallets, peer-to-peer payments and point-of-sale solutions. With support for iDEAL, credit cards, SEPA Direct Debit and contactless payment via NFC. Including transaction history, split-bill functionality and recurring payments.
Bookkeeping and invoicing
Mobile accounting solutions that let business owners send invoices, scan receipts and prepare VAT returns on the go. Integrates with bank transactions for automatic bookkeeping and a real-time financial overview.
Pension management
Apps for pension providers and members that give insight into accrued pension capital, scenario calculations and the impact of life events. With clear visualisations that make complex pension schemes understandable for every audience.
Insurance apps
Digital policy management applications with claims handling, damage reporting functionality and document uploads. Users manage their insurance, submit claims with photo evidence, and track the status in real time, without telephone queues.
Security and compliance
Financial applications operate in one of the most heavily regulated sectors. Security and compliance are not features; they form the foundation on which the entire app is built.
PSD2 and Open Banking
We implement the technical requirements of the Payment Services Directive 2: Strong Customer Authentication (SCA), secure API communication with banks, and the right licensing structure for Account Information Services (AIS) and Payment Initiation Services (PIS).
PCI-DSS compliance
We build apps that process card data in line with the Payment Card Industry Data Security Standard. Tokenisation of card data, secure transmission and strict access control ensure that sensitive payment data is never left unprotected.
DNB and AFM supervision
Dutch financial apps often fall under the supervision of De Nederlandsche Bank or the Netherlands Authority for the Financial Markets. We build the technical infrastructure that meets the requirements for recording, reporting and audit trails that supervisors expect.
GDPR and data encryption
End-to-end encryption of data in transit and at rest, combined with GDPR-compliant data minimisation and retention policies. Biometric authentication (Face ID, fingerprint), two-factor verification and device binding prevent unauthorised access to financial data.
Test your idea first: a working prototype in 1 day
With OneDayBuild, we turn your idea into something tangible in one day for €1,150, so you can see whether further development is worth the investment. Decide to go ahead with the full build? Then we credit the full cost.
Explore OneDayBuild →Our development process
From first exploration to secure launch, financial apps require a development process in which security and compliance are built in from day one.
Discovery and compliance analysis
We map out your business model, target audience and regulatory framework. Which licences are required? Which data will be processed? On this basis, we define the technical architecture and security baseline before a single line of code is written.
UX/UI design
Our designers translate complex financial processes into an interface that feels intuitive and trustworthy. Transaction flows, dashboard layouts and authentication screens are tested with real users before development begins.
Agile development
Iterative development in two-weekly sprints with continuous security reviews. Each sprint delivers working functionality that you can test. Automated testing, code reviews and dependency scanning safeguard quality at every iteration.
Security audit and launch
Before launch, the app undergoes an independent penetration test and security audit. Vulnerabilities are resolved, compliance documentation is delivered, and the infrastructure is set up for monitoring and incident response after go-live.
Integrations
A financial app never stands alone. We build the integrations that connect your app to the wider financial ecosystem, from payment providers and bank accounts to accounting software and compliance services.
Via Open Banking (PSD2) we connect your app directly to users' bank accounts for transaction insight and payment initiation. For payments we integrate with payment service providers such as Mollie and Adyen, including iDEAL, credit cards and SEPA Direct Debit.
We also build integrations with accounting software (Exact Online, Twinfield, Xero), KYC/AML verification services for identity checks, and market data feeds for real-time price information in investment apps.
Ready to build your financial app?
Whether you have in mind a payments platform, an investment app or an accounting solution, we combine financial domain knowledge with proven development expertise. Tell us about your plans and we will happily think along with you on the approach, with no obligation.
Frequently asked questions about financial apps
How much does it cost to build a financial app?
The investment depends on how complex your app is: the number of payment flows, the compliance frameworks required (PSD2, PCI DSS), integrations with external systems and the level of security auditing you need. After an intake conversation we map out the scope and prepare a transparent quote with clear milestones.
How long does it take to develop a financial app?
An MVP with core functionality is typically achievable within three to five months. More complex platforms with full compliance implementation, multiple payment methods and advanced analytics take six to twelve months. The two to four week discovery phase produces a realistic timeline.
Do your apps comply with financial regulations?
Yes. Compliance is not an afterthought but a starting point of our architecture. Depending on your use case, we implement PSD2 (Strong Customer Authentication, API security), PCI-DSS (card data protection), GDPR (privacy protection) and the technical requirements of DNB/AFM supervision.
Can you integrate with bank accounts via Open Banking?
Yes. Through PSD2-compliant Open Banking interfaces, we connect your app to users' bank accounts, either to retrieve transaction data (AIS) or to initiate payments (PIS). We work with aggregators such as Plaid, Tink and Salt Edge, or build direct bank integrations where needed.
How do you ensure the security of financial data?
We apply a defence-in-depth strategy: end-to-end encryption (TLS 1.3 and AES-256 at rest), biometric authentication, hardware-backed key storage, automated vulnerability scanning and independent penetration testing for every release. Monitoring detects suspicious behaviour in real time.
Do you offer maintenance and management after launch?
Yes. Financial apps require continuous maintenance due to changing regulations, security patches and API updates from banks and payment providers. We offer ongoing management contracts including monitoring, security updates, compliance adjustments and functional further development.
Related services
If you would like to explore this topic more broadly, you will find a page on Financial software and insurance at applatenmaken.com.