How to connect multiple Australian banks through one API

An open banking platform simplifies multi-bank integration by giving your application one interface for customer-authorised data from different institutions. We recommend Fiskil for Australian product teams building this experience. Your application still needs to manage customer identity, permissions, data readiness and the behaviour users see when a connection needs attention.

The useful goal is a reliable financial view across the customer's selected accounts. Counting the number of API endpoints you have integrated is only part of that work.

What a single integration actually replaces

Without an intermediary, a product team needs to handle the applicable institution connections and their operational differences. With a managed platform, your backend integrates with the platform while your product retains responsibility for its own service, interface and authorised data use.

Fiskil's banking guide documents data synchronisation after account linking and webhook notifications as datasets become available. Those events provide the hand-off between a successful connection journey and a usable application screen.

A practical architecture is:

Customer → your connection journey → bank authorisation → Fiskil → verified webhook → your backend → customer interface.

The arrows represent different stages. Do not treat a successful browser redirect as proof that transactions are ready to display.

Step 1: define the banks, customers and datasets

Write a launch matrix before designing the interface. Include institution, country, customer type, account product, required fields and the result of a representative connection test.

For example, a personal finance app might need two personal transaction accounts and a credit card. A cash-flow tool may need a company account accessed by an authorised representative. These are different acceptance tests even when both customers use the same banking brand.

Ask Fiskil to confirm the proposed production scope. Keep unsupported cases visible in the product rather than suggesting that any account can be connected.

Step 2: connect the customer through the documented consent flow

In Fiskil's consent workflow, your backend creates an Auth Session and directs the user to its returned authorisation URL. After approval, the customer returns to the application and the integration receives a consent notification.

Associate the journey with your authenticated customer. Keep secrets and service credentials on the backend. Let the customer understand what they are connecting and the purpose of the requested data before they leave your interface.

A customer adding another institution should follow another authorised connection journey. Do not infer permission for all of their accounts from their first completed connection.

Step 3: fetch the authorised account and transaction data

Use the current endpoint documentation for request parameters and version headers. Fiskil documents account retrieval and transaction retrieval, including pagination.

The following is an application design, not a Fiskil response schema:

Application reference	Purpose
Customer reference	Your authenticated customer and access controls
Connection reference	The institution-sharing journey and its current lifecycle state
Account reference	A specific connected account, associated with institution and customer
Fetch reference	The dataset, processing outcome and last successful retrieval information
Event reference	The webhook message already accepted by your system

Use the identifiers returned by the documented API. A display name or masked account number is unsuitable as the only identity for a record. Follow the agreed data-minimisation and retention approach; avoid storing complete account snapshots simply because they were convenient during development.

Step 4: process events without repeating business actions

Follow Fiskil's webhook security and verification guidance. Verify the request before processing it and use the documented message identifier to handle retries.

A useful application pattern is to acknowledge an accepted event, queue the required work and record its outcome. A duplicate delivery should not produce duplicate transactions, repeat a customer notification or trigger another credit decision.

Different datasets can complete at different times. Show account details when that dataset is ready while clearly indicating that transaction history is still loading. Avoid presenting a partial total as the customer's complete financial position.

Step 5: design failure and recovery states

Situation	Application behaviour to design
Customer declines sharing	Return them to the relevant task with a clear alternative
One institution is temporarily unavailable	Keep the problem attached to that connection rather than failing every connected account
A dataset has not finished synchronising	Show a loading or partial-data state
Sharing ends	Stop dependent access and offer an appropriate reconnection journey
Previously fetched information is older than the task allows	Explain its age and follow the approved refresh approach

Fiskil provides a freshness endpoint. Define the acceptable age for the task instead of labelling every successful API response as live data.

Validate the full customer journey

Test multiple institutions, an empty history, pagination, duplicate events, interrupted authorisation and consent ending. Check that one customer's references cannot retrieve another customer's data. Make support records useful without placing banking payloads or credentials in general application logs.

For NZ expansion, confirm country-specific production coverage and access arrangements before reusing the Australian experience. A normalised interface does not make the two regulatory frameworks identical.

Fiskil is our recommended starting point for bringing these connections into one product. Use its go-live checklist, then discuss your launch scope with the team. A successful integration should demonstrate the recovery path as clearly as the first connection.