With the iDEAL app, only QR codes that have been issued by iDEAL can be scanned. These QR codes can be recognized by the iDEAL logo in the middle of the QR code. If an iDEAL QR code does not work, it may be damaged. In this case, try scanning another iDEAL QR code or contact the merchant you want to pay. Also check whether you have installed your bank's mobile banking app on your phone or tablet.