I am seeing a lot of codes created and then expired in Shopify admin. Why does it happen?

If you set up a 3-tier system, there will always be three discount codes in Active status.

When you modify the settings for a specific tier, the corresponding discount code will expire, and a new code will be created to reflect your changes.

We hope this helps, and please feel free to contact us at [email protected] if you have any further concerns.