How to mask your number to protect your privacy?

4 August 2025 | 6 mins read

A person wearing a white mask holding a smartphone with an active lock screen.

Between us… You care about your privacy, don’t you? 😎 So let me share with you some tips to keep your number from becoming the star of marketing databases. More specifically, how to keep your phone number to yourself, away from prying eyes. Gone are the days when your number roamed free like a celebrity without bodyguards! 🕵️‍♂️ Let’s dive into the world of call masking!

🤫 How to mask your number to protect your privacy? The ultimate guide!

As you know, we live in a hyper-connected world today… It’s great, but it also has its downsides. Our personal information, especially our phone number, has become a real currency. According to a recent study, over 53% of web traffic comes from mobile devices, highlighting how central our smartphones are to our lives. Therefore, it’s more important than ever to know how to mask your number.

Whether you want to avoid harassment, protect yourself during online sales, or simply keep a clear separation between your professional and personal life, hiding your phone number is an essential skill to master. And the good news? It’s super easy!

✨ The art of temporary call masking: The famous #31#

This is THE basic technique, the foundation of anonymous calling. Do you have a single call to make without revealing your precious number? No worries, the solution is very simple.

A young man in animated style wearing a white mask and a grey hoodie, looking at his phone in an outdoor market.

The magic code: #31#

Imagine: you need to call a somewhat persistent customer service, or respond to an online ad without wanting to be called back at odd hours. That’s where the prefix #31# will come in handy.

How does it work in practice? It’s child’s play!

Grab your phone (it’ll be better with 😅)
Type #31# followed, without spaces, by the phone number you wish to contact
For example, to call 0612345678, dial: #31#
Initiate the call, and there you go! ✨

Your contact will see "Private number", "Unknown", or "Blocked call" displayed on their screen. It’s quick, effective, and completely free. It works on all smartphones, whether you’re an Android user or a die-hard iPhone fan, and with any operator.

Anecdote: I’ve lost count of how many times I’ve played pranks on my friends or parents by calling from a withheld number, using an app that alters my voice 😂

It’s the perfect solution for occasional needs, but be careful, you have to remember each time. One slip, and your number shows up! If you’re looking for a more "permanent" solution, keep reading, the next part should interest you.

🥷 Switch to ninja mode: permanently hide your number

Tired of typing #31# every time? Do you want ALL your calls to be from a private number by default? It’s entirely possible, and it’s done directly in your smartphone settings.

A young man with an animated style wearing a white mask and a grey hoodie, looking at the camera while holding a smartphone in a crowded street.

📱 How to call from a withheld number on Android?

The steps may vary slightly depending on your phone brand (Samsung, Xiaomi, Google Pixel, etc.), but the principle remains the same. Generally speaking:

Open the Phone app
Tap the three small dots in the top right to access the Settings
Look for an option like "Phone Accounts", "Call Settings" or "Additional Services"
Find the line "Show my Caller ID" or "Caller Identity"
Select Hide Number. And there you have it!

From now on, all your outgoing calls will be anonymous. No more stress! 😎

📱 How to hide your number on iPhone?

With Apple, it’s even simpler, hiding your phone number is even more straightforward:

Go to your iPhone’s Settings
Scroll down and tap on Phone.
Select Show My Number.
Simply toggle the switch.

When it’s grey, it means you are in withheld number mode. Easy, right?

Quick comparison of anonymous SMS sending solutions

Method	Advantages	Disadvantages
#31# (one-off)	Fast, simple, universal	Must be repeated with each call
Settings (permanent)	"Set it and forget it", constant protection	May be an obstacle for receiving calls

A friendly tip: If you mask your number permanently, remember to temporarily reactivate it if you're expecting an important call and want the person to identify you. This will help you avoid ending up in blocked numbers!

🛡️ Alternatives: apps and services for tailored privacy

Need to go even further? Maybe you have a professional activity that requires juggling multiple numbers, or you just want an extra layer of protection. I have solutions for you!

A man wearing a white mask, a dark jacket, and a blue t-shirt, speaking into the receiver of an old-fashioned black phone, with a city street in the background.

Virtual number apps

Apps like our site Anonymous SMS, TextNow, or UnCall allow you to get a second phone number, often for free or at a low cost. This is probably the best way to mask your main phone number.

The advantages:

Work/life separation:
Use one number for work and keep your personal number for loved ones.
Online protection:
Sign up for websites or services without ever giving your real number
Flexibility:
Change your virtual number whenever you want

It's like having a disguise for your phone! 🦸‍♂️

VoIP services (Voice over IP)

Services like Viber Out or TextNow also allow you to make calls to landlines and mobile phones. By purchasing a bit of credit, you can call anywhere in the world, and your temporary number will appear instead of your personal number.

Real-life anecdote: I have a freelance friend who uses a virtual number for all his clients. This allows him to avoid being disturbed on weekends and keep his personal number secret. Clever, right?

An important point to note: Using a private number is an excellent way to protect yourself. Many applications focus on the security and encryption of your communications, which is a real plus in our digital world.

🔎 The other side of the mirror: managing the masked calls you receive

Now that you’re a pro at making masked calls, let’s talk about the opposite situation. What to do when YOU receive a call from a masked number? It’s sometimes intriguing, often very annoying.

Can you call back a masked number?

In general, the answer is no. If someone has taken the trouble to hide their number, it is very difficult, if not impossible for an individual, to call them back directly.

However, some operators offer a service that allows you to call back a masked number within minutes of the call. But this is not a universal solution and its effectiveness may vary.

How to unmask masked numbers? Mission (almost) impossible!

Let’s be clear: it is nearly impossible to unmask masked numbers reliably. Services that promise to do so are often ineffective. Only the relevant authorities can potentially trace the origin of a masked call within a specific legal framework.

So, what to do?

The best strategy is prevention. Most smartphones allow you to automatically block calls from unknown or masked numbers.

The benefits:

On iPhone:
Go to Settings > Phone > and enable Silence Unknown Callers.
On Android:
Open the Phone app > Settings > Blocked numbers and enable the option to block unknown callers.

These calls will be sent directly to your voicemail without even ringing your phone. Pure bliss! 🧘‍♀️️

A man wearing a white mask and a hoodie is looking at his mobile phone in a city street. The image is created in a cartoon or comic style.

💪 Why hiding your number is very important for your privacy

Beyond the technical aspects of how to hide your number, it’s important to understand the concrete benefits for your peace of mind.

The benefits of phone anonymity:

Protecting your personal data:
Your number is the key to many of your online accounts. Protecting it means protecting your digital identity.
Avoiding telemarketing and spam:
This is the number one reason for many of us. By not giving out your number indiscriminately, you drastically reduce the number of unsolicited calls.
Securing your online transactions:
When selling an item on a classifieds site, using a private or temporary number prevents you from being contacted months later.
Maintaining professional distance:
Ideal for professionals who contact clients from their personal mobile.
Keeping control:
In the end, it’s you who decides who can reach you and when. That’s the real luxury!

Protecting your privacy is not a luxury, it’s a fundamental right in the digital age. By learning how to hide your phone number, you take a big step towards regaining control over your data.

🕵️‍♀️ Conclusion: It’s your turn, secret agent!

And there you have it! You now have all the tools to master the art of masked calling. We’ve covered together:

The ultra-simple technique of #31# for occasional needs.
How to set up your iPhone or Android to permanently call anonymously.
The apps and services that offer even more flexibility and security.
How to react to masked calls you receive and the impossibility of unmasking hidden numbers.
All the benefits you gain from hiding your phone number to protect your privacy.

Hiding your phone number is no longer a secret to you. It’s a powerful and easy-to-use tool to navigate more smoothly in our connected world.

So, the next time you hesitate to make a call, remember these tips. Take back control of your privacy, one call at a time! Don’t hesitate to share this guide with your friends, they also have the right to be secret agents! 😉

🤔 FAQ: The questions everyone is asking.

Q1: Does masking my number also work for SMS?

No, unfortunately. Tricks like #31# or phone settings only work for voice calls. Your SMS will always display your number. For anonymous SMS, you need to use dedicated apps, and conveniently, that’s exactly what our service Anonymous SMS offers.

Q2: If I call anonymously, can the person still leave me a voicemail?

Absolutely! If you reach their voicemail, you can definitely leave a message. The only difference is that the person won’t see your number displayed.

Q3: How can I tell if #31# worked?

The best way is to test it on a friend's phone (with their permission, of course!). You’ll see immediately if the call displays as "Private Number."

Q4: Is there a difference between "masked number" and "private number"?

For the user receiving the call, there is no practical difference. Both terms mean that the caller's identity is not displayed.

Q5: Is it possible to unblock the "Show my number" function if it is greyed out on my iPhone?

Sometimes, certain operators may block this option. If that's the case for you, a quick call to your customer service might resolve the issue.