Requiring at Least One Contact Field in eForm

Not every form should force users to fill every contact field. In many cases the real requirement is simpler: at least one reliable way to respond must be provided.

The source question asked how to make one of several fields mandatory, typically a phone or email field. That is a common eForm need and a good example of validation that is better expressed as one logical rule than as several isolated required fields.

The goal

Instead of marking every field as required, validate the group as a whole:

• email is present, or
• phone is present

Practical approach

Handle this in a custom validation step or callback before the form is accepted. If both fields are empty, return a validation message and preserve the entered values.

if (empty($fields['email']) && empty($fields['phone'])) {
    $fields['validationmessage'] = 'Please provide at least one contact method.';
    return false;
}

Why this is better than over-validating

Users complete forms more reliably when the rule matches the real business need. If one contact method is enough, forcing both only increases abandonment.

This small validation pattern is still useful in Evo projects that rely on classic eForm flows for callback requests, quote forms, and lead capture.