Stealth SIMs Explained: A Closer Look at Spoof Phones and Anonymous SIMs

by Brandon Ackroyd - , Last Updated on August 15, 2019, Buying Guides

Tracking of mobile use and data is ubiquitous in the UK. In fact, the UK has some of the laxest laws allowing law enforcement to access your data. For most of us, this isn’t a big deal. But some people prefer a little privacy, and that’s where stealth SIMs come in. Don’t know what a stealth SIM is? We’re here to tell you all about them.

Stealth SIMs: The Basics

Stealth SIMs aren’t exactly easy to get a hold of, though you can buy them online. They’re particularly popular with the criminal element since they allow for more anonymity. In basic terms, a stealth SIM lets you make calls and not be tracked, and we’ll get into the hows and whys below. But the main thing you should know about a stealth SIM is that it gives you (or whoever’s using it) complete privacy.

One thing to note is that many stealth SIMs do not allow you to receive calls, only to make them. This is not always true, but it’s a rather obvious disadvantage to having a stealth SIM…

What Are the Advantages of a Stealth SIM?

There are a few pretty serious advantages to using a stealth SIM card, though a stealth SIM isn’t an option that most of us would choose:

Buyer Anonymity

The first advantage is a simple one, but one that the criminal element, in particular, are interested in, and that’s buyer anonymity. In many countries, the UK included, you’ll need to show some kind of ID to get most SIM cards, and that can be true for PAYG SIMs as well as contract SIMs. The phone company will then have a record of who a certain phone number is connected to, so if problems arise they’ll know that phone number X is linked to person Y.

However, this is not true in all countries. In some places, such as Russia, for example, you do not have to show ID to get a SIM card. So the first advantage of a stealth SIM is anonymity, you will not need to show ID to get it, and there will be no record of your identity being connected with this phone number or SIM card. Many of these SIM cards are bought legally from mobile operators in countries that don’t require ID for purchases (though the cards themselves may be ‘hacked’ after purchase to provide further advantages that we’ll get to below).

This already gives you a certain level of protection. But if you’re, say, kidnapping someone or robbing a bank, simply anonymity isn’t going to be enough of a selling a point. Stealth SIMs do have other advantages though…

Lack of Geo-Location

A stealth SIM will not allow anyone to see where you’re calling from. The way this works is pretty complicated, but in essence, your SIM card will be untraceable. When you make a call using a regular SIM, your phone connects to the closest cell phone tower and hooks onto the network. This makes it easy for someone to see where you’re calling from (because your phone, your SIM card, and the cell phone tower all have unique identifying features that law enforcement can use to identify exactly where you are).

A stealth SIM, on the other hand, won’t simply connect to the closest phone tower. Basically, if you’re using a stealth SIM, your call will be re-routed through different towers and (generally) through a virtual switchboard (often operated by the company that you bought the SIM from, though you can set up your own if you’re very tech-savvy). This makes it impossible to trace where a call is coming from. The SIM card will also mask its own identity, and since there’s nothing connecting you to the SIM card anyway (since you didn’t need to present ID when purchasing), then there’s complete anonymity.

Using a SIM card means that the call you place could be coming from anywhere in the world, and there’s no way for anyone, law enforcement included, to know where you are placing the call from.

Lack of Identifying Number

Additionally, a stealth SIM will allow you to mask your phone number when making a call. Because that call you’re making is going through a virtual switchboard, that switchboard can be used to do one of two things. Firstly, you can eliminate the number you’re using completely so that the person receiving the call thinks it’s coming from an anonymous number. Secondly, you can change the number that appears, so that the person receiving the call thinks that it’s coming from a completely different number.

Again, the process that achieves this is pretty complicated. But the result is an untraceable phone call (or text message).

Additional Benefits

Some stealth SIMs also come with other benefits. These include encryption of all calls, or perhaps voice changing tech that allows you to hide your voice. You’ll be paying premium prices for such features but for some people, complete privacy is worth paying for…

Given the strong security involved, it should be no surprise that stealth SIMs are very popular amongst thieves, hackers, gang members and other criminals. However, spam companies and cold-calling companies may also use stealth SIMs. Some reputable people may use a stealth SIM, such as law enforcement or security service agents. And even some regular people use them, particularly those that are very concerned about privacy…

Are They Legal?

Okay, there’s a grey area here, and please remember that we’re really not qualified to give legal advice. However, for the time being, it seems that stealth SIMs probably are legal in the UK. There are no specific laws forbidding them. And unlike in other countries, such as Germany or Norway, where anonymous SIMs (bought without presenting any ID) are illegal, anonymous SIMs are not forbidden in the UK, so by extension, it seems that stealth SIMs must also be fine.

That doesn’t mean that you can’t get into trouble though. There are all kinds of crimes connected to mobile use, spamming, and even cold-calling, as well as regular criminal activity that is made easier with a stealth SIM. Any crime committed using your phone is still a crime, whether you’re using a stealth SIM or not.

How Do Stealth SIMs Work?

A stealth SIM accesses normal mobile phone networks but makes use of some inbuilt features called (USSD for user interaction/control and CAMEL for routing and handling. It does this to mask its location and true identity from anyone receiving calls from it.

USSD or unstructured supplementary service data is a data transmission and receipt service offered by GSM networks. It used to communicate with a network to retrieve account data. A stealth SIM subscriber can specify the outgoing number range himself and number replacement is implemented via the USSD command.

CAMEL functions permit the handset to be registered with a company automated switchboard so that calls made to an extension within the company can be automatically routed to the mobile handset and calls made from a mobile handset to be sent via the company switchboard.

With a stealth SIM, the user dials a number, a SIM card applet catches the call and redirects it to the service number. The calling number is transmitted onto the SIM providers automatic telephone system (PBX) via an encrypted signal channel. All outbound calls from a secure SIM card are transferred onto a service number of the stealth network and the PBX forwards the call to the end-user.

How Can I Get One?

You won’t be able to walk into a mobile phone store and purchase a stealth SIM. You’re most likely to make your purchase online, and to go through a company that will take care of all the technical details for you (such as setting up that virtual switchboard). There are many sites that offer to sell stealth SIMs, and we’re not going to make any recommendations for obvious reasons. Have a look around.

But do be aware that stealth SIMs are a legal grey area and therefore the companies that provide them may not always be the most trustworthy sources. If you can, try and find customer reviews before purchasing…

In terms of price, a stealth SIM isn’t going to come cheap. Depending on the company you go through you’re looking at paying around £100 or so for the SIM, and then you’ll need to pay for service on top of that. In general, you’ll get what amounts to a PAYG SIM that you’ll need to add credit to.

If you’re looking into purchasing an anonymous SIM card (which you can do through multiple sites, including eBay) you’re looking at paying around £50 or so, but you’ll then need to set up the tech side of things yourself to make this a stealth SIM…

Do I Want One?

Truthfully, no, you probably don’t want a stealth SIM card, and this is for a few reasons:

  • Stealth SIM service is far more expensive than regular SIM card service
  • There’s a good chance that your mobile service won’t be as good as you’d expect from a regular mobile company (for all kinds of reasons, including the fact that re-routing and encrypting calls and texts takes time, making for delays in conversations)
  • Many stealth SIM companies do not allow incoming calls
  • It’s still possible to be relatively anonymous by buying pre-paid SIM cards, where your identity will not be connected to your phone number (though note that these cards, bought at convenience stores generally, will still track your location)

Stealth SIMs: The Bottom Line

If you’re security and privacy-conscious then you might find stealth SIMs popping up on your radar every now and again, particularly as pop up advertisements when you’re online. If you’re interested in going with a stealth SIM, then you’re probably in the clear legally. However, the cost and the fact that service is likely to be slow means that a stealth SIM probably isn’t going to be a decent choice for most mobile users.

Yes, privacy is important. But there are other ways of ensuring that your data is secure, including using encrypted messaging services and the like. A stealth SIM, for now, is probably only a good choice for those who are really up to no good, and we’re going to assume that does not include you!