A Free Number For WhatsApp Is A Really Bad Idea (Here’s Why)

WhatsApp is an app used by millions of people worldwide daily. The messaging service uses your smartphone as its primary platform and your phone number to ensure your identity. Because Facebook owns WhatsApp, people are concerned about their privacy, leaving many wanting a separate free number for Whatsapp.

Getting a free number for WhatsApp is against the company’s terms of service. Users who get a free virtual number are open to potential security and privacy risks. Users should use a mobile number they own or a secondary phone number purchased via a subscription.

No matter your personal privacy preference, you should understand the pros and cons of using WhatsApp with a free virtual phone number. I have seven crucial reasons you should not use a free number and a guide below showing how to get a second number for use with Whatsapp.

7 Reasons Not To Use A Free Number For Whatsapp

Let’s first go over why using a free number for WhatsApp could get you banned or even hacked if you try to use a free phone number for your account.

Against WhatsApp’s Policy

WhatsApp’s service FAQs state that during registration, “you can only verify a phone number you own…using a supported phone number. Unsupported phone numbers can’t be registered on WhatsApp and include: VoIP,” among others.

The company runs phone numbers through a reference database during registration and denies the verification if particular sets of free online numbers are marked as VoIP. Users attempting to use free numbers may encounter the hassle of guessing and checking to find a valid number.

Suppose the company discovers you are using a virtual number. In that case, it may suspend your account until you can provide proof of ownership, like through a subscription invoice. Again, using an unsupported number can become a pain when using WhatsApp’s service.

Besides being counter to WhatsApp’s policies, there’s a more significant danger to you and your online accounts.

PII Indexing Or Enumeration

Unfortunately, since the widespread adoption of smartphones, subscribers’ mobile numbers on Public Switched Telephone Networks (PSTN) have become tightly linked with their identity. They are now considered personally identifiable information (PII).

This coupling of identity is counter to what the US government’s National Institute of Standards and Technology (NIST). The agency published that

use of the PSTN for out-of-band verification is RESTRICTED.

NIST Special Publication 800-63B. 5.1.3.3

The document goes on to clarify that “verifiers SHOULD consider risk indicators such as device swap, SIM change, number porting, or other abnormal behavior…”

When the free number is marked as available, an attacker can search the number using various OSINT techniques. The hacker may find pieces of your identity along with others that have used the phone number before you.

For you, this means that the threat actor can impersonate and potentially gain control of your identity with proper verification and by providing proof of SMS message receipt.

In addition to getting your identity, users of free or disposable phone numbers risk losing their WhatsApp account to hackers.

Account Hijacking Through Recovery Options

Let’s pretend that you create a WhatsApp account using a free virtual number and successfully verify on WhatsApp. Here’s the potential hack scenario:

1. After a short time, your free number can be put back into the pool of available numbers for someone else to use.
2. A hacker can use the list of available numbers to find associated WhatsApp or other online accounts.
3. The attacker uses account recovery options to hijack the account, removing it and all future messaging from your control.

Any of your contacts will continue to believe they are communicating directly with the legitimate you. But in fact, messages are being sent by the attacker impersonating you. This situation becomes a hazard for your contacts.

Phishing Your Whatsapp Contacts

As the hacker impersonates your identity through WhatsApp, they can phish the people you contact for information and get them to act on “your” (impersonated) requests.

Your contacts may unknowingly give up their or more of your personal information to the attacker. Divulging more sensitive information like address, date of birth, financial information, and other online credentials leads to identity theft.

Most hackers are skilled at social engineering and may be able to convince your contacts to act upon requests, presumably to help you. They may be influenced to send money, install malware, or do various other actions that they might not have done if asked by a stranger.

Your reputation and people’s trust are pretty valuable, but even you could be fooled through another phishing vector.

Phishing You Over Whatsapp

In our previous example, the free online number you used to register for a WhatsApp account is returned to the pool of available numbers. An adversary finds the number and can target you using their WhatsApp account.

Because you registered via a free number, scammers can use various social engineering techniques to get you to divulge more of your information or creatively persuade you to take action.

It’s likely that a phone number where you don’t pay for its use also comes with little support from the provider. This lack of support from the service provider and WhatsApp can leave you vulnerable with little help or recourse for resulting damages.

There are even more mundane outcomes from not having control over your WhatsApp account.

Previous Users’ Spam Messages

You have no control over who and for what the free number was previously used. This includes any messages, contacts, or (potentially illegal) activities used on and off WhatsApp by the previous user.

When you sign up for WhatsApp with a previously used number, you’re likely inheriting spam and smishing messages that may continue. As it is, we all receive robocalls and spam texts that must be carefully handled.

You’re signing up to handle all the garbage WhatsApp messages from any previous users who used the free number before you.

Even if you don’t mind wading through and marking messages as junk, this phone number may have already been marked as spam and blocked in WhatsApp. What good is registering for WhatsApp with a free number if you’re already on the blocklist?

The best case for this registration is that it works without a problem. The next problem occurs if your account is banned or taken away from you.

Lose Your Messages, Conversations, & Media Data

If you lose access to your WhatsApp account, your data is no longer in your control. All the texts, photos, audio messages, video clips, and all the associated history is also gone.

We want to hope the company has our best interests at heart. Since you’ve signed up for the account with a free number that’s likely in the “unsupported” category, it’s unlikely that WhatsApp will care much about preserving your data in case of a ban.

No, your best bet is to follow WhatsApp’s policies and use a number you own which entails paying for it. This does not mean that it has to be expensive or tied to a mobile service provider’s contract – it just means you have control over the phone number.

There are cheap options to explore.

The Best Inexpensive Phone Number For Whatsapp

I have a Google Pixel, and I’ve long wanted to test how to add another number to my device using the secondary available embedded SIM or eSIM slot.

After some research, US Mobile offers the most affordable service (in the US) with immediate activation via eSIM. I just tested activating a new number and then registering for WhatsApp using the following steps.

Setting up a US Mobile account

1. Go to US Mobile’s site in a new tab.
2. Click the Talk & Text option (which is all we need for WhatsApp)
3. On their getting started page, they can help verify that your phone is compatible with eSIM activation or “Instant Activation.”
4. Fill in your information, then continue in the registration process.
5. Go through the wizard and verify your email address.
6. Select the “Start my free trial” option from your account dashboard.
7. On the “Activate my trial page,” click the “Instant eSIM activation” option, then click Continue with activation.
8. Go to your smartphone’s settings, locate the IMEI for the eSIM slot, and then enter it on US Mobile’s site to verify your phone’s compatibility.
9. Continue the activation process and select a new phone number. 
   Pro Tip: I chose a number in one of the least populated area codes, western Nebraska (308), to have the best chance of getting a lightly used phone number.
10. For payment information, I created a private virtual card using Privacy.com.
11. It takes only a few minutes to provision your number. 
    Important: While you wait, set your plan to Talk & Text.
12. Once you receive your activation email with the QR code, let’s install your USM eSIM.

Adding an eSIM to an Android smartphone

1. Go to Settings and search for “sims,” then tap the SIMs result.
2. Next to SIMs, tap the large plus button + button.
   
3. On the “Connect to mobile network” screen, at the bottom, tap “Download a SIM instead?” then click Next.
4. On the “Confirm your network” page, tap the “Use a different network” option at the bottom.
   
5. Scan the QR code you received in your email. It’s best if you have the email up on another device.
6. Tap the Download button on the “Use USM?” screen.
   
7. Once it’s finished, tap Settings.
8. Tap the USM SIM option to turn it on.
9. Choose the “No thanks” button when asked to use Verizon (US Mobile is an MVNO) for data.
10. Critical Step: Select the SMS preference option and then tap Verizon so we can receive the WhatsApp activation SMS next.

Using your eSIM to register a WhatsApp account

1. Download, install, and open WhatsApp on your smartphone.
2. Go through the registration steps, and enter your US Mobile number on the “Enter your phone number” screen.
   
3. If you set Verizon/US Mobile as your preferred SMS preference in the previous section, you’ll receive an activation text.
4. WhatsApp may automatically activate, or you may have to enter this code into WhatsApp manually.
5. Privacy Tip: Select the “Not Now” button when WhatsApp asks for access to Contacts and media. You’ll be giving the Facebook-owned messenger all your private contacts. 😲
6. Click the “Cancel” button when asked to restore a backup.

This is an inexpensive way to have a different WhatApp phone number from your primary number. This compartmentalization will help separate your identity on WhatsApp.

There’s a flaw in this method: US Mobile now has some of your personally identifiable information.

There’s an even more private way to get a secondary phone number for WhatsApp.

Even More Private WhatsApp Number

I’ve written about how to get a burner phone and use it securely, but for the purposes of having a second number just for WhatsApp, the process can be reduced to some simple steps:

1. Find a retailer that offers a cheap prepaid dumbphone with inexpensive service.
2. Purchase a device and the minimum call and text plan they offer.
3. Once activated, you can use the number to register a WhatsApp account.
4. Mark on your calendar when the prepaid minutes and texts expire and recharge the service plan.

Paying even a small fee means you’re fulfilling the ownership requirement and have the assurance that the phone number won’t be recycled and then reassigned.

Do you know what doesn’t work…

Burner Phone Apps Don’t Work For WhatsApp (I Tested It)

Some people won’t want another electronic device and would instead use a virtual number on their primary smartphone. Many will turn to some burner phone apps that provide a very short-term and cheap option for temporary phone numbers.

I tested using Hushed by buying a number for $2.00 for 7 days of talk and text to register with WhatsApp. I chose a 308, Nebraska phone number as I did with the US Mobile example from earlier.

After installing the Hushed mobile app, I tried registering for WhatsApp.

It didn’t work. Here are the full steps I used to test Hushed with WhatsApp (with screenshots).