I’m not actually sure since I never had issues, but I’ve heard it’s not much since they’re basically just an API for transferring money between banks. Each bank app still needs to integrate with the network separately. [1]
I guess you get some security since each party that you transfer to must have their identity verified with a bank, so you could always get the police involved fairly easily
The iDeal website page on security [2] is in Dutch, but it translates to roughly:
> Before you make a purchase, make sure that the webshop or business is a reliable party. For example, you can read experiences of other consumers about webshops on comparison sites. Or you can use a Google search to check what is said (in reviews) about a webshop on the internet. Also check the overview of the police with known rogue trading parties and the page check seller data. Before making a purchase, always use the following rule of thumb: if something is too good to be true, don't do it.
