10 Digit Phone Number Validation in Angular in 6 Quick Steps

6 Steps to Angular Phone Number Validation

Let's take a close look at how the phone number validation works in Angular.

Step 1: Create a New Angular App Step

First, you have to create and install angular app. You need to run the following command in the terminal:

Once the command is executed, it will generate a skeleton new Angular project within the my-new-app folder. 

Step 2: Install the Bootstrap Library

Now, you have to install the Bootstrap library in the Angular app. Simply run this command:

Then you have to go to the angular.json file and add these lines:

That's it! You have installed the Bootstrap library in the Angular app. 

Step 3: Add the Code on App.Module.ts File

Now, you have to go to src > app. Here, you will find the App.Module ts file. Open it and add these lines to create reactive forms:

Here, you are importing all the required modules, including BrowserModule, NgModule, and ReactiveFormsModule for creating the reactive form.

Step 4: Add the Code on View File

In this step, you have to create simple form . Open the app.component.html file and add these lines:

Step 5: Add the Code On app.component.ts File

Next, you have to open app.component.ts file and insert this code: 

Here, you have imported FormBuilder, FormGroup, and Validators packages. Also, you have defined the form with the FormGroup. Then you have used the Regex to specify the mobile number validation pattern. 

Step 6: Start the Angular App

Finally, you can start the Angular app. Simply run this command:

Alternatives to Using Angular Mobile Number Validation

There are a variety of alternatives to building validation logic from scratch.

Besides using Angular's built-in validators, another common approach is to use a JavaScript validation library. A very popular choice for this is Yup, a schema builder that simplifies complex validation rules for forms. While this guide focuses on Angular's tools, you can learn more about this method in our dedicated guide on Yup phone number validation.

However, the most suitable one is APIs. They can help you to validate phone numbers easily and quickly. 

You can consider using a lightweight and super-fast API, like Abstract's Phone Validation API. It can perform the verification in just a few seconds. 

Let's verify this phone number with Abstract's Phone Validation API: 14154582468

If the given phone number is valid, you will get this response: 

Here, "valid" is set to true. That means the given phone number is valid. Also, it returns several key information, like international format, country name, and carrier. 

As you can see, there is no need to write any code from scratch. You don't even have to use Regex. You just need to pass the API key and the phone number. The API will deal with the rest. So, Abstract's Phone Validation API can make your life a lot easier. It eliminates complexity effectively. Also, it can enhance your productivity significantly. 

Read: Top 10 Free Phone Validator APIs

Wrapping up

Now, you have learned the way of performing validating phone numbers in Angular. You can use Regex to define the number pattern and the validator package to perform the verification. However, the easiest way is using Abstract's Phone Validation API. It enables you to validate phone numbers effortlessly. 

Phone Number Validation FAQs

How do I verify a phone number?

You can verify a phone number by using Abstract's Phone Validation API. It comes with built-in functions for performing the validation effortlessly. So, you don't have to do anything from scratch. You just need to pass the API key and the phone number. The API will complete the verification in seconds and send the result in lightweight JSON format. It is the easiest way of validating a phone number, 

What is number validation?

Number validation is the process of verifying a phone number. It enables you to identify whether the number is accurate or not. Also, it helps you to improve the quality of your contact list by appending data points like country, carrier, and line type. By validating phone numbers, you can identify and reach real clients, which is vital for growing your business.

What is validation in Angular?

Validation in Angular refers to client-side form validation. The framework monitors the state of the form. It lets you notify the user about the current state. The form has various fields, like input, radio, select, etc. For each of them, you need a FormControl class. The FormControl object gives information about the specific field. It helps you to understand whether its value is valid or not. Also, it provides information about validation errors. 

Frequently Asked Questions

Which Angular validators enforce an exact 10-digit phone number?

The article uses four validators together on the phone field: Validators.required, Validators.pattern("^[0-9]*$"), Validators.minLength(10), and Validators.maxLength(10). Combining min and max length with a digits-only pattern means the field rejects both short numbers and any non-numeric characters before the form can be submitted.

Why use Angular Reactive Forms instead of template-driven forms for phone validation?

Reactive Forms give you programmatic control over form state through FormBuilder and FormGroup, making it straightforward to compose multiple validators on a single control. The guide configures the phone field entirely in app.component.ts, keeping validation logic out of the template and making it easier to unit-test. Template-driven forms can handle simple cases, but reactive forms scale better when you need to combine required, pattern, and length rules simultaneously.

What does the keypress handler do and why is it needed alongside Validators?

The keypress handler tests each keystroke against the pattern /[0-9\+\-\ ]/ and suppresses any character that does not match before it reaches the input. Angular's Validators only flag the form as invalid after input has already been accepted; the keypress handler prevents invalid characters from appearing in the field at all. Using both together gives immediate feedback at the UI level while still enforcing correctness at the form-model level.

How do you add Bootstrap to an Angular project for this validation UI?

After running npm install --save bootstrap, you update angular.json to include Bootstrap's CSS in the styles array and its JavaScript bundle in the scripts array. The guide uses Bootstrap classes to style the form and to conditionally display red error messages when a field is touched and invalid, without requiring any additional CSS of your own.

What are the limitations of regex-based phone validation, and when should you use an API instead?

A regex like ^[0-9]*$ with fixed length constraints confirms that input is numeric and the right number of digits, but it cannot tell you whether the number is actually assigned, reachable, or associated with a real carrier. The article notes that Abstract's Phone Validation API goes further by returning country, carrier, and line-type data in seconds, making it the better choice for production applications where contact quality and fraud prevention matter.

How does Abstract's Phone Validation API complement the Angular form built in this guide?

The Angular form handles client-side formatting checks, but you can fire a request to Abstract's API on form submission to verify the number against live carrier data. The API returns structured information including whether the number is valid, its country of origin, carrier, and line type, giving your application server-side confidence that a correctly formatted number is also a real, active one. This two-layer approach keeps the UX fast while ensuring data quality in your backend.