How to Add a New Confirm Field Validator?

When customers type sensitive information at checkout — like an email address or a custom account number — a single typo can cause real problems: failed order confirmations, missed communications, or incorrect records that are difficult to trace back and fix.

The Confirm Field Validator feature in Checkout Field Editor for WooCommerce solves this by letting you require customers to enter the same value twice and automatically checking that both entries match before the order is placed. It’s a simple but effective way to catch input errors at the source.

A confirm field validator is a rule that compares the value of one checkout field against the value of another. If they don’t match, the customer sees a validation error and cannot proceed until the values are identical.

Like custom validators, confirm validators are configured once in Advanced Settings and then appear in the Validations dropdown when creating or editing a checkout field. You assign the validator to the confirmation field — not the original field.

Each confirm validator has four parts:

1. Go to WooCommerce → Checkout Form → Advanced Settings.
2. Scroll to the Custom Validators section.
3. Fill in the four fields in the Confirm field validators row.
4. To add more confirm validators, click the + button. To remove one, click the × button.
5. Click Save Changes.
6. Open the confirmation field in the field editor (e.g., your Confirm Email field) and select the newly created validator from its Validations dropdown.

Use Case: Preventing Email Typos at Checkout

Order confirmation emails are one of the most critical touchpoints in the post-purchase experience. If a customer miskeys their email address — transposing two letters, for instance — they won’t receive the confirmation, shipping updates, or invoice. By the time they contact support, the order may already be fulfilled to an address they can’t access.

Adding a Confirm Email field paired with a confirm field validator eliminates this risk entirely. The customer must type their email address twice, and if the entries don’t match, they see a message like “Email mismatch”. The order cannot be placed until both fields are identical, ensuring your store always has a valid, intentionally entered email address on record.

This same approach works for any field where accuracy matters: a custom account number, a referral code, or a VAT registration number.

Important: Confirm field validators only trigger when the confirmation field contains a value. To ensure the validation always runs without exception, mark the confirmation field as Required in its field settings. Without this, a customer could leave the confirmation field empty and bypass the check entirely.

Note :In our Checkout Field Editor plugin, the confirm field validation is triggered only when the customer clicks the Place Order button during checkout.