5 Ways to Implement Phone Number Validation in jQuery

Validating phone numbers is a key part of maintaining clean data. We'll walk through five approaches for phone number validation in jQuery, with working code for each. We also examine the common drawbacks of these methods and show how Abstract API addresses these shortcomings effectively.

How to Implement Phone Number Validation in jQuery

Here are a few common ways to validate phone numbers with jQuery. Each method offers a different approach to ensure the data you collect is accurate and well-formatted.

Regex-Driven Validation with jQuery Events

This approach first strips every non-digit character from the input value. Then, a compact regular-expression checks the cleaned string for a country code and correct length. This two-step process keeps the pattern readable and fast.

You can chain the handler to `keyup` or `blur` events to give users immediate feedback. The same handler can also query `element.validity` if you use an HTML pattern attribute.

const rx = /^1?\d{10}$/;
$("#phone").on("blur keyup", function () {
    const raw = $(this).val().trim().replace(/\D/g, "");
    const ok  = rx.test(raw);
    $(this).toggleClass("is-invalid", !ok);
});

The jQuery Validation Plugin

The plugin includes a built-in `phoneUS` rule located in the `additional-methods.js` file. You can also register your own rules with `addMethod` for other regions. Validation is declarative, and the plugin normalizes optional fields and adds ARIA error markup automatically.

$("#form").validate({
    rules: {
        phone: { required: true, phoneUS: true }
    },
    messages: {
        phone: "10-digit US number required"
    }
});

The intl-tel-input Plugin

This plugin renders a country picker and formats the number on-the-fly. It is a jQuery wrapper around libphonenumber-JS. For validation, it calls either `isValidNumber()` or `isValidNumberPrecise()` to confirm the number's authenticity based on international numbering plans.

const iti = $("#phone").intlTelInput({
    initialCountry: "auto",
    utilsScript: "/intl-tel-input/js/utils.js"
});
$("#btn").on("click", () => {
    if (iti.isValidNumber()) submitForm();
    else  showError(iti.getValidationError());
});

Challenges of jQuery Phone Number Validation

While these jQuery methods offer a starting point, they face significant hurdles in real-world scenarios. The dynamic and complex nature of global phone numbering plans exposes their inherent limitations.

• A single regex pattern cannot account for over 200 national plans. This approach fails with varied lengths, optional prefixes, and diverse user input styles, which leads to frequent validation errors.
• Front-end scripts lack the context to interpret complex dial rules. For example, some prefixes depend on the caller's location or network, a detail a simple jQuery script cannot know.
• Numbering plan data becomes outdated quickly. Plugins like intl-tel-input require constant updates to their metadata to remain accurate. Without these updates, the validation produces false results as carriers change networks.
• Client-side validation only confirms syntax, not reachability. A number can appear valid according to a pattern or library like libphonenumber but still be disconnected, which leaves you with false positives.