> Shopify Plus: > [Checkout UI extensions](/docs/api/checkout-ui-extensions) that render on the information and shipping and payment steps in checkout are available only to stores on a [Shopify Plus](https://www.shopify.com/plus) plan. This guide introduces custom banners and fields, and describes the available resources that you can use to build them in Shopify checkout. ## How it works You can build functionality in your app that allows merchants to display and configure the following experiences: - [Custom banners](#custom-banners) in checkout - [Custom fields](#custom-fields) in checkout ### Custom banners A custom banner is a notice that you can display to customers. For example, you might want to show a banner that indicates that items are final sale and can't be returned or exchanged. You can use a [checkout UI extension](/docs/api/checkout-ui-extensions) to build a custom banner. You can support [static targets](/docs/api/checkout-ui-extensions/latest/extension-targets-overview#static-extension-targets) so that extensions can be rendered using the checkout editor in one of the [supported locations](/docs/api/checkout-ui-extensions/latest/extension-targets-overview) in checkout. The following example shows how to display a banner that renders at the [`purchase.checkout.block.render`](/docs/api/checkout-ui-extensions/latest/apis/extensiontargets) target.  ### Custom fields A custom field is a property that allows users to enter text into a user interface. For example, you might want to create a custom field that collects delivery instructions from customers. You can use a [checkout UI extension](/docs/api/checkout-ui-extensions) to build a custom field. The following example shows a custom field that collects delivery instructions and renders at the [`purchase.checkout.shipping-option-list.render-after`](/docs/api/checkout-ui-extensions/latest/apis/extensiontargets) target: ## Getting started Follow tutorials to learn how to build custom banners and fields.