Problem
When using the Gravity Forms Coupons Add-On, you can limit the number of times the coupon can be used overall, but you can not limit coupon usage per user.
Thanks to a user request, I came up with a couple of simple solutions.
Solution
#1 Use the No Duplicates feature.
This is a built-in feature that can be enabled for certain fields. If you enable this feature for the email field, the form will fail validation until you enter another email address.
#2 Using the gform_validation filter
This snippet uses the gform_validation filter to compare the email address to the coupon code entered. If the email has already been used to claim that coupon code, the submission validation fails, and a custom validation message is shown.
Add this code to your themes functions.php file or a code snippet plugin and follow the instructions in the code comments.
Need More Help?
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