In a survey by Human Inference processes were discovered to be the most challenging data quality aspect.
Since in processes often unique identifiers are used to identify customers, accounts or data in general the reliability of these identifiers influence the quality of your process. To avoid incorrect results and decisions a check of the data related to the identifiers is required. The illegal use of such an identifier leads to polluted data. A name-number-check should be implemented for e.g.:
bank account numbers
social security numbers
chamber of commerce numbers