Generally speaking, quality labels should not be compared with M-Check. Quality labels are based on self-defined standards. Producers are assessed on the extent to which they comply with these standards as part of an audit process. Certification thus means that a product meets the requirements of the standard in question.
M-Check is not a standard, but rather a method of assessing products based on a defined list of criteria. Products do not receive certification with M-Check; instead, they have their performance rated.
As the product assessments use the same criteria and the same methodology, this ensures that all products can be compared with one another. This can of course also be said for products bearing a quality label.
The advantage of the M-Check system is that fish do not just arrive in the store with or without an "ASC" label, but rather with more detailed information regarding their sustainability.
As a result, M-Check provides transparency. For example, different MSC-certified products can be awarded a different number of M-Check stars, even if they have always featured the same label on their packaging.