Shopify applies discount codes at checkout. Adding a notice to your cart reassures customers that their discount will be added on the next page
When it comes to the cart notice, there are three main options:
1. Choose not to display a cart notice
2. Display the cart notice as an in-text message:
3. Display the cart notice as a fixed banner on the cart page:
To change the text of the discount notice, navigate to Settings >> Text labels
To choose what type of discount notice to display, navigate to Settings >> General and choose from the options for Cart notice mode.