> For the complete documentation index, see [llms.txt](https://script-and-theory.gitbook.io/all-in-one-commerce-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://script-and-theory.gitbook.io/all-in-one-commerce-docs/checkout-blocks/blocks/custom-checkout-fields.md).
# Custom Checkout Fields
**Description:**
The Custom Checkout Fields block allows you to add additional fields to the checkout form, enabling you to collect extra information from customers, such as special instructions, delivery preferences, or custom messages. This feature helps businesses gather essential details to enhance the checkout experience.
**How to Use:**
* Create a New Block:
* In the app, navigate to the Blocks section.
* Create a new Custom Checkout Fields Options block.
* The system will generate a unique Block ID for this block.
**How to Enable:**
* Go to the Blocks section in the app settings. Copy the created checkout Upsell block to generated Block ID.
* Go into the store customizer
* Then you need to "add app block" and search extension "Checkout fields, Gift, and Address validation" and add it. Click to added extension block and enter the Block ID in the block settings and save the configuration.. **Check Screenshot**
* Set the location where the Custom Checkout Fields should appear on the checkout page.
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