Hey there! Unfortunately, it’s not possible to perfectly segment customers by the use of dynamic coupon codes. (Here’s an explanation why.) There is a workaround, though! 

You could create a segment with the following conditions:

• AND
• lOpened email zero times over all time where the filter is for the specific campaign the code was sent with
• OR
• Placed Order zero times after the date the code was sent]

Essentially, this assumes they haven’t used the coupon because they haven’t bought anything since receiving it. This would also include customers who couldn’t have possibly used the code because they never opened the email with the code in the first place. This may not be perfectly accurate but it should get you pretty close.

We have a course that covers building a loyalty program using only Klaviyo data you might be interested in. In the short term, you might also want to consider using a flow for this process. 

Hope this helps!