It would be nice to be able to setup "expected payments" and get notifications if those payments don't arrive.

I see two main scenarios for this could work:

1. Expect a one-time payment: I send a customer an invoice and they have until some fixed date to pay for it (for example 90 days). So I setup an expected payment to a certain account, with a set amount, a deadline, and (optionally) an expected string in the description (so I can keep bills apart that happen to have the same amount). If I don't receive such a payment until the end of the specified day I get a notification from bunq telling me that I need to act.

2. Expect recurring payments: It would work just like scheduled payments, but instead of making a payment it would check at the end of the specified day whether a payment has been made to a certain account, with a certain value, and (optionally) a certain string in the description. If such a payment doesn't happen raise a notification so I know I need to act.