How to customize checkout fields in WooCommerce

Open the Checkout page in WordPress and check whether it contains the WooCommerce Checkout block or the [woocommerce_checkout] shortcode. The traditional field hooks and most older checkout-field snippets apply to the shortcode checkout, not automatically to the block checkout. WooCommerce says block customisations that add fields usually need separate integration work.

If you are using the block checkout, either use a field editor that specifically confirms block support or prepare to use WooCommerce's additional checkout fields API. Do not paste a classic-checkout snippet into a block checkout and assume it worked.

Decide whether you need to rename an existing field, make it optional, remove it, add a billing or shipping field, or collect separate order information. Keep the checkout short: every required field adds another reason for a customer to stop.

Give each new field a unique internal name, a clear label, a suitable field type and a decision about where its value must appear, such as the order screen, customer email or admin email.

For a classic shortcode checkout, place a small snippet in your child theme's functions.php file or a snippets plugin. WooCommerce confirms that the woocommerce_checkout_fields filter can change labels, placeholders, required status and visibility. For example: add_filter('woocommerce_checkout_fields','site_checkout_fields'); function site_checkout_fields($fields){$fields['billing']['billing_phone']['label']='Mobile number';$fields['billing']['billing_phone']['required']=false;unset($fields['order']['order_comments']);return $fields;}

You can add a billing or shipping field to the same array. WooCommerce automatically processes and saves fields defined there with the checkout field data. A field placed elsewhere on the page needs separate code to render it, validate it and save its value to the order.

For the Checkout block, use WooCommerce's additional checkout fields API rather than the classic woocommerce_checkout_fields approach. WooCommerce documents the woocommerce_register_additional_checkout_field() function for this purpose, and the feature requires WooCommerce 8.9.0 or later. Register the field after WooCommerce has loaded, then define its location, type, label, validation and sanitisation.

If your requirement is only to collect a straightforward extra value, a compatible field editor is usually less maintenance than writing and updating this integration yourself.

Place a test order using the same checkout type your customers use. Check the field on the order edit screen, the thank-you page and the relevant customer or admin emails. Also test an empty required field, invalid input, a mobile screen and a checkout with a different billing or shipping country.

A common failure is seeing the field on screen but finding no value in the order. That usually means the field was rendered outside WooCommerce's recognised checkout field array without separate save logic, or the customisation was written for the shortcode checkout while the page uses blocks.

For drag-and-drop editing, conditional logic, multiple field types and field ordering, install and activate WooCommerce Checkout Field Editor, then open its checkout-field settings. Add or edit a field, choose its label and type, set whether it is required, arrange its position and save the changes. This is the fast route when you need more than a couple of code edits.

Confirm that the product supports your checkout implementation before changing a live store. Some WooCommerce field-editor documentation still limits particular extensions to the legacy checkout, while block support varies by extension.