If your invoice is still unpaid 3 days after its creation or after 2 failed charge attempts, you account will be flagged as delinquent.
If your account is flagged as delinquent, your reward program will continue to work and your customers will still be able to log in to their account. However there are a couple of caveats:
- Customers will not be able to redeem their existing credit.
- Customers may stop to receive new credit.
Also you should note that if you pay your invoice after your account is flagged as delinquent it can take sometime before your account gets back to normal.
In order to avoid these annoyances it's recommended that you check regularly that your payment details are up to date.