If you use many NFC or RFID cards in your everyday life, you might sometimes notice that they don’t function properly, and if you keep them all in your wallet, as most people do, you might wonder whether they are somehow interfering with each other. Is this even possible? When these cards are near each other, does this hinder them from being able to swipe into your office, or use contactless payment? The short answer is — yes! This can actually happen, and in practice often does. In this article, we’ll explore the causes of this issue, and offer ways to address it, and make sure that it doesn’t cause you a headache every time you reach for your wallet.
What causes the interference?
In this section, we’ll discuss what causes the NFC/RFID interference, and why it might happen in your wallet.
NFC/RFID Technology Overview
We’ve already covered NFC and RFID tech extensively in another article, so this will only be a short summary. Basically, NFC and RFID technologies rely on radio waves to transmit information — RFID actually stands for radio frequency identification. NFC is just a subset of RFID, with more strict rules and standards applied to it, making it more secure and making the transmission of information faster.
They exist concurrently with Bluetooth technology, with some major differences. First off, NFC only works at very close distances, whereas Bluetooth can work up to about 100 feet apart, depending on the strength of the device. Also, more importantly, NFC allows for one of the communicating devices to not need a power supply. This is the distinction between active and passive devices.
Active vs. Passive Devices
As mentioned, one of the main advantages of NFC technology is that one of the two communicating chips doesn’t need to have a power supply. This is the passive device of the pair, and it can actually draw power from the active device using electromagnetic induction.
What happens here is that thanks to the proximity requirement of NFC, the active device can use magnetism to generate electricity inside the passive device’s coils (the ‘antenna’ in the above image), which will power up the NFC chip, and allow it to communicate with the active device.
In practice, this manifests itself as NFC cards and readers. Readers are the active devices, given that there is no issue with them having a permanent power supply, but NFC cards don’t have one, and don’t even have the capability to have one — how would you plug it in, and where would it store power? A separate power source would make it too bulky to fit in a wallet or badge holder. As a result, NFC cards have passive chips, and rely on proximity to readers to induce a current in them, which prompts them to transmit their ID information.
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“Crossed Wires,” Except with Wireless Tech
While the distinction between active and passive devices discussed above is surely an amazing innovation and allows for a much wider expansion of NFC standards, the one downside to it is that it often results in NFC interference, when you have multiple NFC cards in close proximity to each other.
This happens because when you approach a wallet or badge holder with multiple NFC cards to an NFC reader, and they all enter into the electromagnetic induction range, the reader will activate them all, irrespective of whether it’s the “right” card or not. This means that they will all begin transmitting their NFC identification information.
A direct result of this is that the active NFC device, the reader, will receive a bunch of NFC ID signals, but it won’t actually know which is the “correct” one. If it happens to receive another one before the intended one, it will think that the first (incorrect) signal was the intended one, and naturally, the signal will not be authenticated.
To ground this in a real example, say you have a contactless NFC bank card and an NFC access card side by side in your wallet. You tap the wallet to the reader at your office, and the bank card’s signal reaches the reader first. The reader thinks that the bank card was the intended access card signal, and naturally will not allow you to enter the building.
How can I address it?
In this section, we’ll explore how, much to everyone’s chagrin, there is no “silver bullet” here to solve the issue of NFC interference. There are, however, some strategies you can employ to make sure that you minimize the rate at which this occurs.
Separate Your NFC/RFID Cards
The first, obvious solution would be to separate your cards. NFC range usually maxes out at around 10cm (around 3 inches), meaning that if your cards are separated by more than that amount there is no risk of interference. You could accomplish this by having one card in your wallet, and another in a badge holder, and keeping them separated by around 2-3 inches when tapping one to a reader.
Even closer than 10cm would be fine, though. In practice, having cards on opposite ‘sides’ of your wallet, and only tapping the proper side of the wallet to the NFC reader, is usually enough. However, this might have more to do with other objects blocking the signal, which brings us to our next method for minimizing interference — putting stuff between your NFC cards.
The Old-Fashioned Method — Aluminum Foil or Enough Other Stuff
Metal absorbs magnetism, that’s essentially what the idea is here. Yes, you’d be correct to point out that it conducts electricity, but that means that it conducts it through the material itself, and essentially stops it if it were going through the air and about to hit it. In this context, if you put the right metal, or enough other metal, between your two NFC cards, even if they are both within range, the metal ‘barrier’ will work as an RFID card separator and absorb the signal of the card farthest away from the reader and will not trigger the wrong NFC chip.
This is why keeping your NFC cards on “opposite” sides of the wallet sometimes does the trick — many credit cards or transit cards, even if they’re not NFC based, have some sort of metal chip or magnetic strip on them, and this absorbs the signal. However, the most common ‘bootstrap’ method, so to speak, to eliminate NFC interference, is to keep a sheet of tin foil sandwiched between your NFC tags. This will totally block the magnetic signal, so all you have to do is present the correct NFC card to the reader (on the correct side of the wallet/badge holder), and you’re all set.
The Modern Method — Signal Absorbing Cards
There are, naturally, more modern and sophisticated ways to block NFC signals than a sheet of tin foil. There are specific cards or chips that you can put in your wallet that act as a piece of tinfoil would. Some are merely fancier looking cards that have aluminum foil lining, and thus block the signal while looking prettier. Others are more tech-enabled.
The card pictured above is one such card. This card, and similar cards, are still passive devices meaning that they don’t have to be charged, and don’t constantly emit an NFC signal. However, they instead have a chip that can still be activated by RFID signals, and when activated transmits a strong signal that drowns out/scrambles any other NFC/RFID signals in its vicinity.
This means that if you want to use those to block NFC signals, when you actually want to unlock a door, or pay with a bank card, you’ll have to take your relevant card out of your wallet and present it separately to the reader. Obviously, this is a hassle — the primary purpose of these cards is simply for protection against piracy or theft. You might have heard of devices that can steal NFC/RFID data. Modern NFC cards are well encrypted, but still susceptible, so devices of this nature make it so that thieves can’t read your cards’ NFC information.
Of course, another method for accomplishing this is sandwiching your NFC cards inside aluminum foil!
RFID interference is certainly an issue, especially with the proliferation of NFC cards on the market today, and all the use cases that they cover. Unfortunately, there’s no magic solution just yet, but with some clever little tricks you can make sure that the issue’s scope is minimized for you.
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How to address RFID NFC interference between cards in your wallet? ›
In this context, if you put the right metal, or enough other metal, between your two NFC cards, even if they are both within range, the metal 'barrier' will work as an RFID card separator and absorb the signal of the card farthest away from the reader and will not trigger the wrong NFC chip.Is RFID blocking necessary 2023? ›
In 2023, the importance of RFID protection in wallets is more significant than ever before. As technology continues to advance, so do the methods that criminals use to steal sensitive information such as credit card data. With contactless payment methods becoming more common, the risk of RFID fraud is only increasing.How do I protect my cards from RFID scanning? ›
- Buy a card sleeve or RFID wallet that blocks RFID transmissions.
- Stack your cards together to mitigate some of the scanner's ability to read information.
- Leave your cards at home and only use cash in public places.
Yes, it is possible successfully block RFID with aluminum foil. It can work by simply wrapping it around your cards or wallet. In fact, many people actually use aluminum foil around their cards' as a homemade, cheap RFID blocker.Can I wrap my credit cards in aluminum foil? ›
The aluminum will disrupt most electronic signals. You can also wrap each credit card in aluminum foil and place the wrapped cards in your wallet. The foil shields the card from scanners.Do RFID blocking wallets block NFC? ›
RFIDsecur RFID blocking fabric is used for the production of RFIDsecur Contactless Blocking Cards. These are superfine cards that can protect all your contactless cards against Bluetooth, Wifi, RFID and NFC, 3 and 4G mobile phone signals.Do RFID blocking wallets really work? ›
But, do they really work? The simple answer is yes! RFID reduces the reader's signal power which prevents the microchip from working. In turn, that means your data is kept safe by making it more difficult to read the information of your ID card, credit card and passport.Why would I want an RFID blocking wallet? ›
Keeping all your cards in an RFID-blocking wallet not only protects you from thieves, but also has the added benefit of blocking card readers' signals to your other cards when you're in the checkout line, or tapping to pay for buses and trains during your commute.Do I need RFID blocking wallet for travel? ›
If you're at low risk, or simply don't use anything that has RFID in it, then you probably don't need RFID protection. For low-risk people that still have cards, passports, or ID you'd prefer to keep under wraps, then investing in some protection could be worth that extra peace of mind to know you're covered.Can my credit card be scanned in my wallet? ›
Yes, if you have a contactless card with an RFID chip, the data can be read from it.
What materials block RFID readers? ›
- Metal: Metal is a highly effective RFID signal blocker, as it reflects radio waves and prevents them from penetrating the material. ...
- Water: ...
- Concrete: ...
- Leather: ...
- Faraday cages: ...
- RFID-blocking materials:
An RFID-blocking wallet uses a layer of carbon fiber or aluminum to block the electromagnetic signal emitted from your card. The wallet acts like a Faraday cage. It creates a barrier and cancels out electromagnetic signals. Whether you've owned a contactless payment card or not, the market for it has grown rapidly.Will a magnet stop RFID? ›
Will strong magnets affect or disable these devices? No. RFID chips send out a radio signal, which is not affected by permanent magnets. While RFID devices can be powered by a changing magnetic field (by electromagnetic induction), they can not be scrambled, erased or blocked with a strong permanent magnet.Does wrapping your phone in tin foil make it untraceable? ›
Sadly, it doesn't work. While wrapping the phone in foil would almost certainly create some degree of interference, it likely wouldn't be enough to prevent the phone sending and receiving signals.What happens if you put a magnet next to a credit card? ›
Credit cards usually use ferrous oxide with a covering of plastic. The plastic protects your card from grazes and scratches. However, if another magnet is held close to your credit card for prolonged exposure, your credit card can lose its functionality and may stop working.How do I protect my debit card in my wallet? ›
To protect your Credit or Debit Cards from damage, you can keep them in card protector sleeves. Most of the time, when you receive a credit card, it comes with a simple plastic sleeve. If you lost that sleeve or didn't get one, you can also make a simple paper sleeve to protect your cards.What is the best way to demagnetize a credit card? ›
Coming into contact with refrigerator magnets, clasps on wallets, and magnets on the back of tape measures and flashlights can demagnetize a credit or debit card. When you place your card in your wallet, but sure not to rub it up against the metal clasp and place it as far away from it as possible.Can I remove RFID from wallet? ›
You can terminate your RFID tag via the TNG RFID Portal or the TNG eWallet linked to the RFID Tag.How do I block NFC signal? ›
Simply place one Signal Flare behind your credit or debit card on each side of your wallet to instantly block RFID and NFC signals that could be trying to access your personal data.What is the difference between RFID and NFC blocking? ›
While RFID refers to radio frequency identification, NFC stands for “Near Field Communication”. While RFID and NFC share the same technology, they're on different frequencies. Another difference is that while RFID is one-way communication, NFC is two-way because NFC devices can act as both a reader and a tag.
How common is RFID skimming? ›
It's a scary thought, but how likely is it to happen? The truth: not very likely, for the following reasons. Most credit card chips are not RFID-capable. Today's chip-embedded credit cards don't actually transmit any information that could be captured without inserting the card in a reader.Do all metal wallets block RFID? ›
Security: Another key advantage of metal wallets is their security. Compared with traditional wallets, these are much more difficult to pickpocket, and also provide protection against RFID (radio-frequency identification) skimming.Are RFID wallets magnetic? ›
Longer answer: RFIDs typical work via magnetic coupling to both power and to transmit data.Is RFID blocking bad? ›
The ITRC says there is nothing wrong with using a RFID-blocking wallet if it provides some extra peace of mind, but warns that it shouldn't take people's minds off the important security precautions they really need to take, like reviewing credit reports regularly and protecting online accounts with strong, unique ...Can RFID go through airport security? ›
The x-ray machines would see the antenna as a piece of metal, and security might question you about it, but the transponder should not have any impact on the performance of security equipment. X-ray machines use a far different area of the electromagnetic spectrum than RFID does.Do credit cards use RFID or NFC? ›
How NFC Is Used for Contactless Payments. Believe it or not, your credit and debit cards emit radio waves. Modern cards are RFID enabled but don't worry; they use near-field communication and require close contact to send signals.What can stop RFID? ›
- Wrap your credit card in aluminum foil. ...
- Purchase an RFID-blocking wallet. ...
- Hold the credit card in your fist.
- Car rental: No-waiting vehicle returns. ...
- Amusement parks: No-swipe ticket passes. ...
- Casinos: Robbery-proof chips. ...
- Sports: Loss-resistant golf balls. ...
- Guns: Safety products. ...
- Smart fitting rooms. ...
- Health care: A hygiene solution.
Metal containers are great for blocking electromagnetic radio waves, and you don't have to do much at all to “build” them into RFID blockers. Just clean out the tin and place your credit cards inside of it. Voila! You have a perfectly adequate RFID blocker!What is the RFID symbol on wallet? ›
If you see a symbol on your card that looks like a radio signal, that means your card has an RFID chip. Designed to facilitate contactless payments, this technology enables you to wave your card at a payment terminal and complete your transaction through the use of RFID signals.
How do I protect my wallet from scanners? ›
A good way to protect your cards is to buy an RFID blocking wallet. This type of wallet contains a layer made from carbon fiber or metal. This special layer inside the wallet blocks the electromagnetic fields from reaching your RFID cards.Is tapping your card safer than inserting? ›
More Secure. Tapping to pay isn't all about making your life simpler, but it also creates a more secure way to shop. By using a mix of chip technology, Near Field Communication (NFC), and Radio Frequency Identification (RFID), tapping to pay is safer than your classic swipe or insertion of a credit or debit card.How do you tell if your card has been skimmed? ›
- Look at the card reader. First, check to see if the credit card reader looks intact. ...
- Inspect the card reader. You can also feel around the card reader for a skimmer. ...
- Check the security seal. At gas pumps, look for possible skimming by checking the security seal near the reader.
You can prevent RFID tag interference/communication by using a faraday enclosure to shield the signal emitting from the tag. Faraday enclosures use a unique material and tight seal in order to block RF signals from both being sent and received by an electronic device, such as an RFID tag.Can you be tracked through RFID? ›
Can RFID tags be tracked? Yes, RFID tags can be tracked. They can be tracked automatically using active RFID tags or manually using passive RFID tags. To be tracked RFID tags provide data related to where they have been and where they currently are.Can RFID go through glass? ›
The special feature of this RFID adhesive label is not just that it can be attached behind glass and transparent surfaces. The data can be read through the glass using the reader developed by S+P Samson. The transmitting range of the RFID label is variable.How do I know if my wallet blocks RFID? ›
How to tell if your wallet is RFID protected? The simple way is to bring it across an RFID scanner/reader while placing the credit card inside it. If you see any signals transmitting, you can tell that the wallet is not RFID protected.How do I know if my card has RFID? ›
If you're not sure whether your card is RFID enabled, you can easily check by taking a look at the card. RFID-enabled cards have a logo on the front or back of the card that looks like a Wi-Fi symbol turned on its side. This symbol is meant to represent the radio frequency used by the card to make it contactless.What interferes with RFID tags? ›
Here are some of the most frequent causes of RFID interference problems: Environmental factors are the most common cause. In the past there were difficulties with tags mounted on metal or on containers of liquids, which interfered with the activation of the tags and resulted in them failing to respond to readers.How do you know if your card is demagnetized? ›
If you find the magnetic stripe on your credit card is no longer working, it may have become demagnetized.
Does stainless steel block RFID? ›
Aluminum, copper, stainless steel, and carbon fiber are some of the materials used to make an RFID blocking wallet. As for metals used, stainless steel has far more advantages than aluminum or copper.How far away can RFID work? ›
Far-range UHF RFID tags can read at ranges as far as 12 meters with a passive RFID tag, whereas active tags can achieve ranges of 100 meters or more.How do I make my phone untraceable? ›
- Lock your SIM Card. ...
- Limit ad tracking on your phone. ...
- Opt-out of carrier tracking. ...
- Disable Bluetooth. ...
- Activate airplane mode. ...
- Disable GPS location services. ...
- Try a GPS spoofing app. ...
- Enable a VPN connection.
The best way to block phone tracking is to use a VPN. But you can also change a few settings on your phone or switch to a different browser to stop tracking. You can hide your location via settings, block ad tracking with a dedicated private browser, and encrypt all of your internet traffic with a VPN.What happens if you put a magnet behind your phone? ›
Magnets can affect the internal magnetic sensors located inside the smartphone and may even slightly magnetise some of the steel inside your phone. This magnetisation could then interfere with the compass on your phone.What happens if you have two contactless cards in the same wallet purse? ›
If you present your purse or wallet to the device and it contains more than one contactless card, the cards will clash and no payment will be taken.How do you scramble an RFID signal? ›
The signal sent out by a RFID tag is easily blocked by metal. This means that placing the RFID tag inside of a Faraday cage will prevent the information from being read.What makes a wallet RFID blocking? ›
RFID-blocking wallets are made from thin, durable metal, such as carbon fiberandaluminum. These special materials prevent unwanted radio frequencies from penetrating the card case and activating the RFID tagon your credit, debit, or ID cards.Do magnets block NFC? ›
No. NFC relies on alternating magnetic (and electrical fields) changing 13560000 times per second. A magnet represents a steady field, or at most one changing at the comparatively low rate at which you could physically move something. There will be no interference in terms of the actual signals.Can someone turn on my NFC? ›
Be Aware of Security Risks From Using NFC
Because it lacks password protection, hackers can access NFC data, and they can even do this without you being aware.
What happens if I touch in with one contactless card and touch out with another on the same journey? ›
What happens if I touch in with one contactless card, and touch out with another on the same journey? It's important that you try to avoid doing this, as you'll be charged a maximum fare on both of your cards. The two separate journeys won't be linked and each one will be recognised as incomplete.Can someone clone your card from contactless? ›
Contactless cards contain an antenna to allow the payments system to identify the card and carry out the transaction. If you are worried about devices reading your card and cloning it, line your wallet or purse with tin foil. This blocks the radio signal needed for the card to communicate.Can two people have the same card on their Apple wallet? ›
Yes, a card can be added to Apple Pay on multiple devices, however the card will need to be added to each device separately. Apple, the Apple logo, Apple Pay, Apple Watch, Face ID, iPad, iPhone, iTunes, Mac, Safari, and Touch ID are trademarks of Apple Inc., registered in the U.S. and other countries.What is the code for RFID blocker? ›
NAICS stands for the North American Industry Classification System, and is used by the U.S. government to classify types of businesses. The code used for RFID firms is 519190 (All Other Information Services).What can interrupt RFID? ›
- Interference. ...
- Power Supply. ...
- Line of Sight. ...
- Reader Antenna. ...
- Humans (and other conductive objects) ...
- Tag Type.
RFID functionality can be disabled permanently by cutting internal wires; the use of a microwave oven has also been reported successful, according to informal reports.How do I know if my RFID is blocking? ›
How to tell if your wallet is RFID protected? The simple way is to bring it across an RFID scanner/reader while placing the credit card inside it. If you see any signals transmitting, you can tell that the wallet is not RFID protected.