How to remove discount code block from magento cart
In order to remove the discount code block you have to open the checkout.xml file which is located in/app/design/frontend/default/[your_theme]/layout/checkout.xml.
If there is no such file, copy it from /app/design/frontend/base/default/layout/checkout.xml to your theme and…
Open the file and delete the following code:
<block type="checkout/cart_coupon" name="checkout.cart.coupon" as="coupon" template="checkout/cart/coupon.phtml"/>
If you want to delete the ESTIMATE SHIPPING AND TAX block, remove the following code from the same file. The code should be just after the previeous line.
<block type="checkout/cart_shipping" name="checkout.cart.shipping" as="shipping" template="checkout/cart/shipping.phtml"/>
That’s all. Do not forget to refresh the cache.