Heiko-Hartwig As far as I know, the monthly limit works on the two fields Creditor ID and Mandate. It depends on the company how they deal with this. I have an insurer that collects different mandates separately and a telecom company that collects various subscriptions with the same mandate.
The biggest problem I have with the monthly limit is when a company's standard debit date falls on the weekend and is at the beginning or end of the month. Then the collection shifts and you get two collections per month. The second are then promptly all rejected and you still have to approve by hand.
The other is when you do not book monthly but every 4 weeks, even then a monthly limit is impractical.
The solution is of course to double the monthly limit, but I find that an illogical solution. Moreover, the app itself does not propose so you have to think about doing this.