Understanding Your Results
A QR scan gives you the real destination URL and checks it against known phishing and malware lists, it does not certify that every "clean" link is risk-free forever. A domain with no history in threat databases yet is not automatically safe; it just means nothing has been reported against it so far.
Weigh the signals together: a URL that does not match the context where you found the code (a parking-meter sticker pointing to a generic-looking domain instead of your city's official site) is a strong signal on its own. A shortened or redirected link that only reveals its final destination after several hops is worth extra caution even if that final destination is not yet flagged anywhere.
If you already scanned a code and entered a password or payment details on the page it led to, change that password immediately and contact your bank or card issuer.