FunnelKit Funnel Builder has a checkout optimization option to ensure that shoppers enter a house or building number in their billing or shipping address during checkout.
This way, it helps reduce failed deliveries and improves address accuracy.
Enable Address Field Validation
Turn this setting on by clicking on the Yes option.

This will activate the validation on address fields.
Enter Validation Message
Customize the message shown to users when the validation fails.
The {{address_field}} placeholder will be automatically replaced by either:
- Billing Address
- Shipping Address
So, if a user forgets to enter a house number in the billing address, they’ll see:
“House/Building number is required in Billing Address”
Save the changes when you’re done and this is how it’ll work:
- The checkout form will check for a numeric value in the address fields.
- If no house/building number is found, the user will be prompted with the validation message and prevented from proceeding until the house number is entered.
Testing the Address Field Validation
This is how the address field validation will appear on the checkout page:

Upon entering the house or building number, you can continue placing your order.
This was all about validating the house/building number in the address fields on your WooCommerce checkout page.