Support for ACSS Debit in Plan Change Flow (Java SDK)

[faezeeghlima]

Hi Stripe team,

I’m working on a Java-based application with a Spring Boot backend and an Angular frontend, which originally supported only card payments. I’m now in the process of adding support for Pre-Authorized Debits (PAD/ACSS Debit) specifically for Canadian users.

Here’s the flow:

For trial users, PAD works correctly.

I’ve implemented an “Add new card” page, where I now also allow users to add a PAD payment method (using a SetupIntent).

After that, users go to the "change plan" page, where they can choose from saved payment methods and confirm the new plan.

The issue:
When a user originally subscribed with a card, adds a PAD payment method later, and then tries to switch to a new plan using that PAD method — the payment fails or does not complete as expected.

My questions:

Is there anything special I need to configure when attaching an ACSS Debit method to an existing customer who initially subscribed with a card?
Does switching from a card-based subscription to a PAD-based one require any additional mandate acceptance or SetupIntent logic during the plan change?
Should I recreate the subscription from scratch when switching payment methods from card to PAD?
For reference, I'm using the Java SDK and updating subscriptions using SubscriptionUpdateParams.

Thanks for your help!