This may be due to two reasons:
1. the name of the legal entity specified in the input data must match the name of the legal entity on the provided document.
2. poor image quality of the provided document: often a photo works better than a scan, make sure it is high resolution and evenly lit, do not use black and white photos. All aspects of the document must be clearly visible.
Detailed information on this can be found in our FAQ article "Bank Account Verification".