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, right? 😎 So let me give you some tips to keep your number from becoming the star of marketing files. More specifically, how to keep your phone number to yourself, away from prying eyes. Gone are the days when your number roamed freely like a celebrity without bodyguards! 🕵️‍♂️ Let’s dive into the world of hidden numbers!

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

As you know today, we live in a hyperconnected world… Well, that’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 just how central our smartphones are to our lives. 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 masked calls: The famous #31#

This is THE basic technique, the foundation of anonymous calling. Got a single call to make without revealing your precious number? Don’t worry, the solution is also very simple.

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

The magic code: #31#

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

How does it work in practice? It’s a piece of cake!

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

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

Anecdote: I’ve lost count of how many times I’ve pranked my friends or parents by calling from a blocked number, using an app that modifies my voice 😂

It’s the ideal solution for a one-time need, but be careful, you have to remember it every 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 private numbers 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 with a blocked 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 little dots in the top right corner 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 go, you’re all set!

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 off.

When it’s grey, it means you’re in blocked number mode. Easy, right?

Quick comparison of anonymous SMS sending solutions

Method	Advantages	Disadvantages
#31# (one-time)	Fast, simple, universal	Must be repeated with each call
Settings (permanent)	"Set it and forget it", constant protection	May be a barrier to receiving calls back

A little friendly advice: If you mask your number permanently, remember to temporarily reactivate it if you are expecting an important call and want the person to identify you. This will prevent you from 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 surely the best way to mask your main phone number.

Advantages:

Separation of work/personal life:
Use one number for work and keep your personal number for loved ones.
Online protection:
Sign up for sites 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 mobiles. By purchasing some credit, you can call anywhere in the world, and your temporary number will appear instead of your personal number.

A personal anecdote: I have a freelance friend who uses a virtual number for all his clients. It allows him not to be disturbed on weekends and to keep his personal number secret. Clever, right?

An important point to note: Using a private number is a great way to protect yourself. Many apps focus on securing and encrypting your communications, which is a real plus in our digital world.

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

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

Can you call back a hidden 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 it back directly.

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

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

Let’s be clear: it is nearly impossible to reliably unmask hidden numbers. Services that promise to do so are often ineffective. Only the competent authorities can potentially trace the origin of a hidden 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 hidden numbers.

The advantages:

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. Royal peace! 🧘‍♀️️

A man wearing a white mask and a hoodie looks at his mobile phone in a city street. The image is rendered 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 advantages 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 freely, you drastically reduce the number of unsolicited calls.
Securing your online transactions:
When you sell 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 are taking a big step towards regaining control of your data.

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

And there you go! You now have all the cards in hand to master the art of masked calling. We covered together:

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

Masking your phone number is no longer a secret for 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 luckily, that’s exactly what our service Anonymous SMS offers.

Q2: If I call masked, 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 know if #31# worked?

The best way is to test it on a friend's phone (with their consent, of course!). You will immediately see if the call shows up 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, a quick call to your customer service could resolve the issue.