November 9, 2023

Bank integrations: Inside-out vs Outside-in approaches

Since we started Acme, we often receive questions like “Are you guys like a Plaid for APAC?”, or “How are you different from the open finance or open banking companies in SEA ”, and sometimes, “Could I use your APIs to access and verify information from bank accounts?”

These sound like questions with binary yes/no answers. We wish it were that straightforward. But answers to questions like these require a bigger unpacking of what bank integrations really mean, and more importantly, how it is done in practice.

For example, in countries where open banking regulations exist to specify that banks need to grant access to account information (in the UK or EU for example), the process of doing bank integrations becomes much easier. 

On the flip side, in countries or regions where open banking regulations do not exist, there are two approaches to bank integrations: An outside-in approach vs. an inside-out approach. 

Outside-in approach

Type of accounts and use case:

  • Typically used to access financial account data or provide account verification (both consumer and corporate accounts)
  • Bank Integration companies provide an authentication flow for users’ to grant permissions to share their financial account data

Bank involvement:

  • Limited or no involvement from the bank whose accounts are being accessed

Speed to market:

  • Scales faster with a one-to-many approach, and works well in countries or regions where clear Open Banking standards exist e.g., the EU

Examples: Plaid (in the early days), Yodlee, Saltedge

Inside-out approach

Type of accounts and use case:

  • Typically used to enhance and accelerate corporate banking use cases (e.g., money movement or reconciliation)

Bank involvement:

  • Bank integration companies integrate directly and individually with each of their customers’ bank accounts
  • Every new integration requires an onboarding process with the bank, where the customer will authorize the bank integrations partner to use their credentials

Speed to market:

  • Scales more slowly with a one-to-one approach, since a formal arrangement has to be signed with every bank

Examples: Modern Treasury, Payable, Finix, Acme

Why Acme

Acme’s product principles are built around taking the hard but predictable way via an inside-out approach. We take every single integration that our customers have with their banks of choice seriously, and our goal is to always deliver a solution that works best for our customers in the long term.

Exploring a direct integration with your bank for bank reconciliation, payments, or payouts? Talk to us ( to see how we can help.