Who's Calling Me from a Hidden Number? Every Way to Find Out, Step by Step

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Your phone rings. You look at the screen and see "No Caller ID." Your heart starts beating a little faster. Who is it? Why are they hiding their number? Should you be worried?

You're not alone. Millions of Israelis face this question every day, and most quickly discover that the standard solutions they find on Google simply don't work when the number is truly hidden. Apps like Truecaller are excellent at identifying regular numbers, but when someone deliberately hides their number, they're powerless.

I'm Tom Aflalo, and I built Traceback specifically to solve this problem. In this article, I'll explain why most solutions fail, what actually works, and how you can know exactly who's calling you, even when the number is completely hidden.

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Photo: Pixabay

Why Most Caller ID Solutions Don't Work with Hidden Numbers

The Technical Problem Most People Don't Understand

There's a huge difference between "unknown number" and "actually hidden number," and understanding this difference is key to understanding why most solutions fail.

When someone calls you from a number that's simply not saved in your contacts, your phone still sees the number. It just doesn't know who it belongs to. In this situation, apps like Truecaller or similar caller ID apps can help - they match the number against their database and tell you if it's a telemarketer, a specific business, or something else.

But when someone deliberately hides their number (by dialing #31# before your number, or by setting permanent number hiding in their cellular account), something completely different happens. The number simply doesn't reach your device. Your carrier's network (Cellcom, Partner, Pelephone, Hot Mobile, Golan Telecom, or others) does see the actual number, but it doesn't pass it to the recipient's device. Any app running on your phone sees only NULL - nothing.

It's like trying to search for something on Google without typing a search term. There's nothing to search for, nothing to identify, nothing to match against a database.

Common Methods That Don't Work (or Only Work Partially)

Truecaller and similar apps: These applications are excellent at what they were built for - identifying regular numbers based on a database of millions of users. But when a number is deliberately hidden? They can't do anything. They simply see "No Caller ID" just like you do, and can't help.

Call return codes *42# or *69: These codes are supposed to call back the last number that called you. The problem? They only work if the caller didn't hide their number in the system. If they dialed #31#, there's nothing to call back. The carrier simply didn't save the number in your history.

Contacting your carrier: Technically, Cellcom, Partner, Pelephone, and the other carriers know who called you - their network saw the number. But they won't provide you with this information. Only to the police, with a court order. To private individuals? No chance.

Blocking hidden numbers in settings: This option exists on iPhone and Android, and it blocks all calls from "No Caller ID" at once. This can be good if you truly don't want to receive such calls at all, but it doesn't tell you who it was. You're still left in the dark.

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What Exactly Is a "Hidden Number" and Why Does It Happen

Different Types of "Hidden"

Not all "hidden numbers" are created equal. There are several different types worth knowing:

Deliberately hidden number (#31#): This is the most common case. The caller dials #31# before your number (for example: #31#0501234567), and the outgoing call is hidden. This works with all Israeli carriers: Cellcom, Partner, Pelephone, Hot Mobile, Golan Telecom, Rami Levy, 019, 012, and others.

Permanently set hidden: Some people (usually businesses or professionals) set permanent number hiding in their cellular account. Every outgoing call from that number will always be hidden, without needing to dial #31# each time. Doctors, lawyers, and certain customer service departments sometimes do this.

Private Number (on iOS devices): On iPhones, the call is sometimes marked as "Private Number" instead of "No Caller ID." It's usually the same thing - deliberate hiding - but the terminology varies.

Spoofing (number forgery): This is a more advanced technology where the caller doesn't just hide their number - they make your device display a completely different number, usually a number of a known organization (bank, credit company, police). This is relatively rare in local calls in Israel, but very common in international scams. It's important to know that Traceback identifies hidden numbers; when a number is already displayed on screen, even if fake, there's nothing to reveal.

Why People Call Hidden

Legitimate reasons:

• Lawyers wanting to maintain client privacy
• Doctors calling patients from the clinic
• Customer service from banks or credit companies (sometimes)
• People who simply prefer to maintain their privacy

Illegitimate reasons:

• Aggressive telemarketing that knows if you see the number, you'll block it immediately
• Repeated harassment
• Phone scams
• Illegal debt collection
• Threats

"Semi-legitimate":

• Someone who wants to make contact but doesn't want you to immediately know who they are
• Not always bad - sometimes it's just shyness, or someone checking if you're available before revealing themselves

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The Method That Actually Works: Conditional Call Forwarding Through Traceback

How It Works (Step by Step)

I built Traceback to solve exactly this problem - to reveal No Caller ID calls when all other methods fail. The solution is based on a technology called conditional call forwarding, which works completely differently from regular caller ID apps.

Here's how it works in practice:

Step 1: Activating Conditional Call Forwarding
You dial a special code on your Israeli phone (something like **61*[number]*11# - the exact code appears in the app). This code tells your carrier: "Forward only calls from hidden numbers to a specific number" (Traceback's number). Regular calls from identified numbers continue to reach you directly as usual.

Step 2: Traceback Catches the Call at the Network Level
Here's the magic: when someone calls you from a hidden number, the call is forwarded to Traceback in the cellular network itself, before the number is hidden. This is the critical point - Traceback doesn't try to "guess" who's calling from an app on your phone. It operates at the stage where the network still sees the actual number.

Step 3: The System Identifies the Real Number
Within seconds, Traceback identifies the original number and sends you a push notification to your device with the full number. You see exactly who's calling.

Step 4: You Decide Whether to Answer
If it's a number you recognize and want to talk to, Traceback returns the call to you within seconds. If it's an unknown number or telemarketer, you can ignore it and save the number for the future to block it.

Why This Works When Regular Apps Don't

Traceback Isn't an App Running on Your Phone
This is the most important difference. Truecaller, similar caller ID apps run on your device - they only see what the device sees. If the number is hidden in the network, they simply can't help.

Traceback, on the other hand, works through the network itself, at the stage where the number is still visible. It's like catching someone before they put on a mask, instead of trying to guess who's behind the mask after they've already put it on.

Conditional Call Forwarding Is an Official Code
This isn't a hack, a trick, or something that might stop working tomorrow. Conditional call forwarding is an official feature that every carrier in Israel supports: Cellcom, Partner, Pelephone, Hot Mobile, Golan Telecom, Rami Levy, 019, 012. No special permissions needed - it's part of the basic cellular network standard.

The Call Isn't Lost
If you don't answer the call (after seeing who it is and choosing not to), Traceback will let it go to your voicemail, just like any regular call you didn't answer. If you do want to answer, it happens within seconds. The call simply passes through Traceback for identification, then returns to you.

Practical Setup (5 Minutes)

1. Download Traceback
Go to the App Store (iPhone) or Google Play and search for "Traceback." Download and install the app.

2. Register with Your Phone Number
Enter your Israeli cellular number. You'll receive an SMS with a verification code - enter it to verify your number.

3. Choose a Subscription
Traceback offers weekly, monthly, and annual subscriptions with unlimited reveals. You can check pricing and full feature list.

4. Dial the Conditional Forwarding Code
The app will display a code to dial (something like **61*[number]*11#). Copy it, open your regular phone app, dial the code, and press "call."

You'll receive a message from your carrier saying "Call forwarding when busy activated" (this is the official terminology - it's fine).

5. You're Done
From now on, every call from a hidden number will pass through Traceback for identification. Regular calls from identified numbers continue to reach you directly as usual, with no change.

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What to Do with the Information After You Know Who's Calling

Now that you know who the hidden number was, what do you do with this information?

Immediate Options

Direct Blocking
If it's a telemarketer calling for the third time this week, or someone you simply don't want to talk to, block the identified number directly on your phone. From now on, calls from them won't reach you at all, even if they don't hide the number next time.

Saving Evidence
Traceback creates a detailed PDF report of every identified call - date, exact time, full number, and duration of the active call. You can generate a PDF report directly from the app, save it to the cloud, or print it.

Important to note: The report is a organized document that can be presented to the police, a lawyer, or the Consumer Protection Authority to document harassment. If the harassment is serious, the police can contact the carrier with a court order and request the official data.

Forwarding to Police (if there are threats or harassment)
If you're receiving calls with threats, sexual harassment, or anything else that crosses the legal line, don't ignore it. File a police report and present Traceback's reports as organized documentation of the calls. The police can investigate the case and request the official data from the carrier.

Reporting to Consumer Protection Authority
If it's illegal telemarketing (a company ignoring your requests to remove you from their distribution list, or marketing at illegal hours), you can file a complaint with the Consumer Protection Authority with Traceback's reports as organized evidence.

When to Do Nothing

One-time Call from Unknown Number
Sometimes someone forgot to cancel permanent number hiding, called once, realized you didn't answer, and didn't come back. If it happened once and didn't repeat, it's likely no follow-up is needed. You know who it was (thanks to Traceback), and can decide for yourself whether to call back.

Numbers You've Identified as Legitimate
If it turned out to be your doctor, a lawyer, or your bank's customer service that was genuinely trying to contact you, no further action is needed. You simply now know who it was, and can call back if necessary.

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Frequently Asked Questions (FAQ)

Does conditional call forwarding cost extra money?

No. It's a regular code that every carrier in Israel supports for free: Cellcom, Partner, Pelephone, Hot Mobile, Golan Telecom, Rami Levy, 019, 012, and others. It's part of the basic cellular network standard. You only pay for the Traceback subscription, not to the carrier.

Does Traceback work on calls from abroad?

Yes. Conditional call forwarding catches international hidden calls as well. The system identifies the call source in the network, regardless of where it came from. If someone calls you from a hidden number abroad, Traceback will identify the full international number.

What happens if I don't want the service anymore?

You can cancel the service at any time. Dial the cancellation code that appears in the app (something like ##61#), and call forwarding will be cancelled. You'll return to the normal state - hidden calls will reach you directly like before (but without identification). The Traceback subscription can be cancelled from the app settings or from the app store.

Does Traceback keep recordings of the calls?

No. Traceback identifies the calling number and forwards the call to you, but doesn't record the call content. If you want to record calls (for example for evidence in a harassment case), you'll need to use a separate recording app. Important: In Israel, recording a call without the other party's consent can be legally problematic in certain circumstances. Consult a lawyer if you're unsure.

Can you identify a spoofed number?

Traceback identifies the number the network sees. In rare cases of sophisticated spoofing (mainly international scams), the identified number might be the spoofed number and not the real one. But in most cases in Israel, the hiding is simple #31# (regular number hiding), and Traceback sees the actual source.

Important to note: If a number is already displayed on screen (even if fake), Traceback can't reveal the real number, because there's nothing to reveal. Traceback reveals calls from hidden numbers, not numbers already displayed on screen.

Do I need to keep the app open all the time?

No. Once you've activated the conditional forwarding code, your carrier's network handles it - it happens at the network level, not the device level. The app needs to be installed (to receive push notifications with the identified number), but it doesn't have to run in the background all the time.

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⚠️ Disclaimer: This article is general information only and does not constitute legal advice. For any specific legal situation, consult a qualified attorney. Traceback is not responsible for legal outcomes.