Ernst While I do not see the reason why you would restrict this, indeed I agree with @Sem that IFTTT makes more sense for private individuals.
Zapier is more business oriented servive , and their business model is 'the user pays', and it is free for bunq as a service provider to integrate. Once you go over 100 tasks (events) per month, you need to pay as a user. It is not difficult to have more than 100 transactions per month, and if you want to do multiple things for one transaction, then you'll get there even faster. With my personal IFTTT integration I have around 600 events per month which would cost me USD 20 per month with Zapier.
IFTTT is more oriented to the private individuals, and their model is that the service provider (bunq) pays for the integration. While it appears an initial developer account to publish one service costs USD 199 per year, it could be that for bunq the costs would be a lot higher than that.
