Conditional field
<input id="billing-toggle" name="useBilling" type="checkbox" />
<input
id="billing-address"
name="billingAddress"
data-validate="billing-address"
/>Conditional demo
Checkout
Conditional billing validation plus required shipping and payment method choices.
Back to demo galleryDeveloper notes
The billing field is only required when another control makes that rule relevant.
Registered rule
validator.registerRule("billingAddress", ({ form, value }) => {
const enabled = form.querySelector("#billing-toggle").checked;
return {
valid: !enabled || String(value).trim() !== "",
messageKey: "required"
};
});