When does dunning not work?

There are three situations where dunning does not take place automatically:

a) When a payment fails for one time charges or addons (added "immediately" and not on the next renewal) applied to a subscription.

b) When an attempt to manually collect a Not Paid invoice fails.

c) When a payment fails during activation (after trial ends).

Find more on dunning management here.

New Solution:

There are two situations where the dunning does not work, they are:

1. When a payment fails for one time charges (added immediately and not on the next renewal) applied to a subscription.

2. When an attempt to manually collect a Not Paid invoice fails.

Refer here to know more about dunning management.