How to remove the Discount Code / Coupon Code box in Magento My cart page?

Solution 1:

Edit your theme's "/layout/checkout.xml" file. Find and Comment the below lines.

Solution 2:

Add new local.xml file under your theme's layout folder.

Here, You no need to search for any template or layout file. This code will do the trick. After making changes dont forget to refresh the cache. That's it. You are done.