“One for all, all for one”: The first part of this motto from the musketeers in the swashbuckling films can – with a slight twist – also apply to modern banking customers: “One app for all accounts.” This is exactly what Multibanking is, an application that many users with multiple accounts appreciate, as it allows them to easily and quickly keep track of their various accounts at different banks. Is it magic? No, API connectivity is the reason why this convenient everyday tool makes financial control so simple.
What is Multibanking?
Multibanking is the process in which users can manage multiple bank accounts from different banks or financial institutions through a central application or platform. This functionality is particularly useful for people who have accounts with various banks, whether due to different financial needs or specialized offers. Connecting these accounts through a central interface saves time and effort and enables more efficient financial management.
Typical use cases of Multibanking
Multibanking demonstrates its added value above all in everyday life – both for private individuals and for businesses. A central account overview is only the beginning.
Private individuals: financial overview and budget control
Many consumers today manage several accounts at once – for example a salary account, a savings account, a joint account, or an investment portfolio held with different banks. Multibanking consolidates these accounts in a single application, providing transparency across assets, income and expenses.
Typical use cases include:
- Viewing all account balances in real time
- Automatic categorisation of expenses
- Budget planning and savings goals
- Analysis of recurring payments and subscriptions
- Preparation for credit or financing applications
Especially in times of rising living costs, multibanking helps users make better‑informed financial decisions and manage spending more consciously.
Businesses: cash‑flow management and accounting
For small and medium‑sized enterprises, self‑employed professionals or start‑ups, multibanking serves as a strategic tool. Having business accounts with different banks is common – for instance to separate operational funds, reserves, or international transactions.
Multibanking enables:
- A central overview of all business accounts
- Optimised cash‑flow management
- Faster liquidity planning
- Automated transfer of account data to accounting or ERP systems
- More efficient coordination with accountants or tax advisers
Thanks to API connectivity, financial data can be integrated seamlessly into existing systems, reducing manual processes and minimising sources of error.
Multibanking promotes transparency, saves time and reduces complexity. It evolves from a mere convenience feature into a strategic instrument for financial management – both privately and professionally.
How does multibanking work technically?
Multibanking is based on standardised interfaces (APIs) that allow financial data to be exchanged securely between banks and third‑party providers. The technical process follows a clearly defined series of steps.
Step by step: how account linking works
The account‑linking process usually runs as follows:
- Selecting the bank
The user chooses, within the multibanking application, the bank whose account should be linked. - Redirect to the bank
The application redirects the user to the bank’s secure authentication environment. - User consent
The user explicitly grants permission for certain account data (e.g. balance, transactions) to be retrieved via an API connection. This consent is time‑limited and can be withdrawn at any time. - Strong customer authentication
For security, strong authentication is required – commonly using two‑factor methods such as app‑based TAN, SMS‑TAN, or biometric approval. - Data retrieval via API
After successful authentication, the bank makes the authorised data available through a standardised API. The multibanking application automatically retrieves this information. - Regular updates
Data are refreshed at defined intervals as long as the user’s consent remains valid.
Distinction I: multibanking vs. traditional online banking
Traditional online banking is limited to the accounts of a single bank. Users must log into each bank separately to check balances or transactions.
Multibanking, by contrast, aggregates several accounts from different banks in one central application. The key difference lies in the cross‑bank aggregation of financial data via standardised interfaces.
Distinction II: multibanking vs. open banking
Multibanking is a specific application within the broader concept of the PSD2‑driven open‑banking ecosystem.
Open banking defines the regulatory and technological framework that obliges banks to grant third‑party providers access to account data via APIs – provided the customer consents. Multibanking is one of the most visible and widely used implementations of this principle.
While open banking provides the infrastructure and regulation, multibanking represents the tangible product that end users experience.
What is a multibanking API – and what is it used for?
A multibanking API is a standardised application programming interface that enables secure, structured access to financial data from multiple banks and, in some cases, the initiation of payment orders. It provides the technical infrastructure that makes multibanking applications possible in the first place.
While multibanking is the visible application for end users, the API serves as the underlying connectivity layer between banks, third‑party providers and digital platforms.
APIs as infrastructure for multibanking
Multibanking APIs act as intermediaries between:
- Banks (account‑servicing institutions)
- Third‑party providers (e.g. fintechs or platform operators)
- End users (private individuals or businesses)
Through these interfaces, account information is provided in a structured format or payments are initiated – always on the basis of the customer’s explicit consent. In Europe, the regulatory foundation is PSD2, which obliges banks to provide standardised access for authorised third‑party providers as part of the broader open‑banking framework.
Types of APIs used in multibanking
Not every API in the financial domain automatically qualifies as a multibanking API; its purpose is decisive.
1. Account‑aggregation API
These APIs enable the retrieval of:
- Account balances
- Account turnovers/transactions
- Transaction details
- General account information
They form the basis for cross‑bank financial overviews and are essential for multibanking dashboards, personal finance apps, or accounting systems.
2. Payment API
Payment APIs go one step further: They allow payments to be initiated directly from a third‑party application – for example individual transfers or bulk payments.
This turns multibanking from a pure information platform into an active control centre for financial transactions.
Roles within the multibanking ecosystem
Multibanking APIs are embedded in a clearly defined role model:
Banks
Provide the account infrastructure and expose standardised interfaces.
TPPs (Third‑Party Providers)
Regulated third parties that may access account data or initiate payments via APIs, provided that customer consent is in place.
Fintechs and platforms
Use multibanking APIs as a technological foundation to build innovative applications such as financial management tools, embedded‑finance solutions or data‑driven services.
Why APIs are the core enabler of multibanking
Without APIs, multibanking would not be technically scalable. In the past, account aggregation often relied on so‑called screen‑scraping methods, which are error‑prone and problematic from a security perspective.
Modern multibanking APIs, by contrast, offer:
- Standardised data formats
- Strong authentication mechanisms
- Encrypted data transmission
- Clear authorisation and consent models
- High scalability for platform solutions
APIs are therefore not just a technical detail, but the central prerequisite for secure, regulatory‑compliant and market‑ready multibanking solutions.
Is multibanking secure?
The question of security is crucial: multibanking processes sensitive financial data, which means the requirements for data protection, encryption and access control are correspondingly high.
In principle, multibanking solutions in Europe are subject to strict regulatory requirements and technical security standards. Three protective mechanisms are key.
1. Access only with explicit consent
No access to account data takes place without the user’s active consent. Before a multibanking application is allowed to retrieve data, the account holder must:
- select the specific bank
- grant access to the data
- authenticate with their bank
This consent is purpose‑bound and limited in time. It can be revoked at any time. Without valid consent, no further data retrieval is possible.
2. Strong customer authentication
- Multibanking uses the same security mechanisms as the online banking of the respective bank. The basis is so‑called strong customer authentication (SCA), which is mandated under PSD2. This means:
To gain access, at least two independent factors are required, for example:
- password or PIN
- one‑time code (TAN)
- biometric feature such as fingerprint or Face ID
The multibanking application itself generally does not store full login credentials for the bank account.
3. Encryption and secure data transmission
Data transmission between the bank and the multibanking provider is encrypted via secure API interfaces. Typically, this involves:
- TLS‑encrypted connections
- certificate‑based authentication
- strict access restrictions
- regular security audits
The systems are designed so that only the data required for the specific service are processed (data‑minimisation principle).
Who can see my data?
A common misconception is that multibanking providers can freely dispose of account data. In reality:
- Only regulated providers with the appropriate licence have access.
- Data may be used exclusively within the scope of the consent given.
- Disclosure to third parties is not permitted without additional consent.
Banks continue to retain control over account management. Multibanking providers merely act as authorised interfaces, not as a new “intermediary bank”.
Conclusion
Multibanking, supported by API connectivity, offers significant benefits for both consumers and banks in terms of efficiency, innovation, and user-friendliness. However, security concerns, technical challenges, and regulatory requirements must be addressed to ensure the long-term implementation and growth of this concept. The development of secure and reliable APIs is key to the success of Multibanking applications and to creating an integrated digital financial ecosystem.
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