Do you have a Discount Rule and a coupon enabled ?
Do you want to prevent coupons from being applied to cart when they have a discount or vice versa ?
Then here are two workarounds which will be of use. 

Workaround 1:
It is possible to disable the discount rules when there is a third party coupon applied in cart.
There is an option in our general settings, Disable the rules while have coupon(Third party) in cart.
Setting it to yes, will disable our discount rules when a coupon is applied. 

Workaround 2:
You can create a coupon in woocommerce with "zero" value and associate that coupon to a discount rule.
In the discount rule, you can set your desired percentage value.
Once the discount rule is created, make sure that you have selected, apply for --> biggest discount from the Settings tab. 

Click here to know more about associating coupons with discount rules.
Attaching a guide detailing the same. 

Still Unclear ?
Feel free to leave your question and email by clicking the Live Chat button below.
We are always happy to assist you :)

Did this answer your question?