What actually makes a QR code stop working?
A QR code only stops working if it depends on a service that goes away. A “static” code has your URL or text baked directly into its pattern. There’s nothing to expire, because there’s no third party involved once it’s printed. A “dynamic” code instead points to a short redirect link controlled by whichever service generated it; scanning it sends you through that service first. If that service shuts down, changes its URL scheme, or discontinues the redirect, the printed code breaks even though nothing about the physical code changed.
How do you tell which kind of code you have?
Check what URL the code actually contains, not just what it says on the screen. Scan it with your phone’s camera before printing anything at scale, and look at the link it opens. If it’s your destination URL directly, it’s static. If it opens a short link from the generator’s own domain that then forwards you elsewhere, it’s dynamic, and its lifespan is tied to that service.
What should you do if you’re not sure?
Regenerate the code with a generator that encodes your URL directly, and test-scan it before printing. The QR code generator on this site, including the Canva-specific version, always encodes your link directly with no redirect service in between, so a code generated here has nothing to expire.