As you can see in the attached image, when I try to update plan on a subscription, I get an error that Subscription cannot be updated as we are not able to collect USD XXX from your card on file. Amount must be atleast 50 cents.
I am selecting the option Invoice Now when updating the plan. I can recreate the issue through Chargebee's dashboard.
Let me know if you need more information. The steps to recreate this issue are not straightforward so I won't be able to provide you an exact scenario where you would see this issue. For this case I am updating the plan from a 3 month renew for $125 to an Annual plan for $550. There are outstanding credits on the user.
You're seeing this error because the transaction charges for this subscription change is 17 cents and the minimum transaction amount that the Stripe gateway allows is 50 cents.
To resolve this issue, you could choose the "Add to Unbilled Charges" option instead of "Invoice Now". The unbilled charges can either be manually invoiced later or it automatically gets included in the upcoming renewal invoice. Does this work?
Alternatively, you could enable the "Round off Invoice Amount" option(Settings>Site Settings>Site Info) if you're okay with the decimal charges being rounded off to the nearest whole number.
We're also working on handling this at our end to ensure it doesn't cause an obstruction in your workflow, however, we currently do not have a firm timeline on it.
Hope this helps.