Why isn't my NFCKEY scanning?

Common causes:NFC is turned off in your phone settingsThe phone is not positioned correctly over the NFCKEYThe NFCKEY is too far from the NFC sensorThe NFCKEY is near a metal surface, which interferes with the signalTry repositioning and make sure NFC is enabled.

GUIDE

Program your NFCKEY with ST25 NFC Tap

Q: Where is the NFC sensor on my phone?

iPhone: top back area, near the camera.Android: usually on the back centre. The exact location varies by model.Hold the NFCKEY against that area for 1 to 2 seconds.

Q: How much data can NFCKEY store?

Storage depends on the chip type:ST25TA64K — 8KB ST25TN01K — 160 bytes The ST25TA64K comfortably fits any link or contact record. The ST25TN01K is best suited to short URLs or plain text, a long link with tracking parameters could bump against the 160-byte ceiling.

Programming your NFCKEY with an STMicroelectronics® chip takes under a minute. No reader hardware, no software licence, no technical setup. Download the free app from STMicroelectronics, write a link, and update it as often as you like. Learn how in this guide.

Works with

STMicroelectronics® ST25TA64K, ST25TN01K and other phone-programmable ST25 chip families offered by NFCKEY.

What you can write

Links, text, vCards, Wi-Fi credentials, Bluetooth pairing, email, SMS, phone calls and geolocation.

Get the app:Download for iPhone Download for Android

Before you begin

Ensure NFC is on

Enable NFC in your phone's settings. iPhones from XS onwards have it on by default.

Check your chip is phone-programmable

ST25TA64K and ST25TN01K are phone-programmable ST25 chips used in NFCKEY. ST25TV16KC requires production-side NDEF formatting and isn't covered by this guide.

See all chip types

Not sure which chip you have?

Download the ST25 NFC Tap app and use "Read Tag" to identify it. It shows chip type, protocol, and memory size.

Step 01

Download the ST25 NFC Tap App

The ST25 NFC Tap app by STMicroelectronics® allows writing tags, adding business cards, storing contacts, pairing with Wi-Fi, or Bluetooth®, enabling hotspots, sending text messages and much more all with just a tap.

On iPhone this app is listed simply as NFC Tap, same app, same developer, STMicroelectronics.

On Android it's listed as ST25 NFC Tap.

Prior to encoding, make sure your phone has NFC enabled in the settings.

Step 02

Read The Keychain's Current Data

1. Launch the app

2. Tap the keychain against the NFC sensor

3. You'll land on the Tag Info page, with details like the manufacturer, memory size, and a few other chip specs

4. From the Tag Info page, switch to the NDEF tab at the top

If the keychain had information already encoded, you will see the record and its size.

If the chip was blank, it'll just show no NDEF messages, 0 bytes.

Step 03

Add a New Record

1. Tap the add button in the bottom right corner

2. Pick the type of record you want to encode:

URI · open a link in the browser
Text · display a plain text message
Bluetooth · quick device pairing
Bluetooth Low Energy · pairing with BLE devices
Email · pre-fill a message to an address
SMS · pre-fill a text message
vCard · save contact details
Wi-Fi · connect to a network automatically
Mime Data · attach a file type such as a PDF
External Data · custom app-defined data
Call · dial a phone number
Geolocation · open a map location

In our case, we're encoding a link, so we select the URI record type.

Step 04

Enter Your Information and Validate

1. Tap the NDEF URI Record option to encode a link

2. Type in the URL you want to encode.

3. Glance at the preview at the bottom to make sure it's exactly right.

4. Tap Save, in the top right corner.

5. Hold the keychain near the NFC sensor until it's encoded.

6. On successful encoding, you'll be back on the NDEF tab, now showing your record and a "Tap updated" note.

Step 06

Test Your NFCKEY

Once you've written the chosen information on the NFC keychain, check its accuracy to see if any changes are required.

1. Tap your NFCKEY to your phone (like any other NFC card) or another NFC-enabled device

2. Check that all contact details or links open as programmed

3. If you notice that you made a mistake or want to change any information, proceed to Step 7. If not, you are done!

In our case, the link has been saved successfully and it appears on the phone screen when NFCKEY is tapped on the phone.

Step 07

If Necessary: Edit Information

If you want to update the information or you notice that you made a mistake, you can easily do so in the same app.

1. Open the app and scan the keychain

2. Go to the NDEF tab

3. Tap the existing record

4. If it's a record you would like to keep but just edit, for example edit the URL. You can tap the existing record and edit it, after all the changes were made, re-encode it on the keychain by saving the record.

5. If it's a record you would like to delete. Hit Delete and confirm to wipe it. Then just add the new record following the steps above.

Step 01

Download the ST25 NFC Tap App

On iPhone this app is listed simply as NFC Tap, same app, same developer, STMicroelectronics.

On Android it's listed as ST25 NFC Tap.

Prior to encoding, make sure your phone has NFC enabled in the settings.

Step 02

Read The Keychain's Current Data

1. Launch the app

2. Tap 'Read NDEF'

3. Hold the keychain near the NFC sensor

If the keychain was previously encoded, the app shows the existing record. If it's blank, it displays "No NDEF record."

Step 03

Add a New Record

1. From the "No NDEF record" section, swipe right to left to reveal the action bar

2. Tap "Add," then choose the type of record you want to store:

URI · open a link in the browser
Text · display a plain text message
Bluetooth · quick device pairing
Bluetooth Low Energy · pairing with BLE devices
Email · pre-fill a message to an address
SMS · pre-fill a text message
vCard · save contact details
Wi-Fi · connect to a network automatically
Mime Data · attach a file type such as a PDF
External Data · custom app-defined data
Call · dial a phone number
Geolocation · open a map location

In our case, we're encoding a link, so we select the URI record type.

Step 04

Enter Your Information and Validate

1. Tap the "NDEF URI Record" option

2. Input your URL, then tap "Validate."

The app returns you to the record screen.

Step 05

Write The Data To Your NFCKEY

1. Tap "Write to Tag"

2. Hold the keychain near your phone's NFC sensor

3. Wait for the checkmark and confirmation that writing is complete

You can rewrite the information on your wearable anywhere and anytime using the app and the NFCKEY.

Step 06

Test Your NFCKEY

Once you've written the chosen information on the NFC keychain, check its accuracy to see if any changes are required.

1. Tap your NFCKEY to your phone (like any other NFC card) or another NFC-enabled device

2. Check that all contact details or links open as programmed

3. If you notice that you made a mistake or want to change any information, proceed to Step 7. If not, you are done!

In our case, the link has been saved successfully and it appears on the phone screen when NFCKEY is tapped on the phone.

Step 07

If Necessary: Edit Information

If you want to update the information or you notice that you made a mistake, you can easily do so in the same app.

1. Go to the main screen and tap "Read NDEF."

2. Hold the keychain near the NFC sensor

3. On the existing record screen, swipe left to right to reveal the "Remove" button

4. Tap "Remove" and the record is deleted

5. Swipe right to left, tap "Add," and repeat Steps 3 to 5 to write new data

Frequently Asked Questions

Yes. NFCKEY works with NFC-enabled iPhones (iPhone 7 and newer) and most Android devices that support NFC.

On iPhone the app is called NFC Tap; on Android it's ST25 NFC Tap. Make sure NFC is enabled in your phone settings before scanning.

After you add your record in the app, but before you write it, the app shows the size next to the write button, for example "Write to Tag (22 bytes)". This tells you exactly how much space your link or record will use before you commit it to the chip.

If the number looks larger than expected, a shorter URL (or removing tracking parameters) will bring it down.

iPhone: top back area, near the camera.

Android: usually on the back centre. The exact location varies by model.

Hold the NFCKEY against that area for 1 to 2 seconds.

Common causes:

NFC is turned off in your phone settings
The phone is not positioned correctly over the NFCKEY
The NFCKEY is too far from the NFC sensor
The NFCKEY is near a metal surface, which interferes with the signal

Try repositioning and make sure NFC is enabled.

Yes. Open ST25 NFC Tap, tap Read NDEF, swipe left to right to reveal Remove, delete the existing record, then swipe right to left and tap Add to write new data. Explained in Step 7 above.

Storage depends on the chip type:

ST25TA64K — 8KB
ST25TN01K — 160 bytes

The ST25TA64K comfortably fits any link or contact record. The ST25TN01K is best suited to short URLs or plain text, a long link with tracking parameters could bump against the 160-byte ceiling.

Yes. ST25 NFC Tap supports text, contact cards, WiFi credentials, Bluetooth pairing, email, SMS, phone calls and geolocation, among other record types. The process is the same for all of them, only the fields you fill in change.

Yes. Both the iPhone and Android versions are free to download.

You need internet access to download the app. After that, writing data to your NFCKEY does not require an internet connection, it works entirely over NFC between your phone and the keychain.

No. Programming is a digital operation that writes data to the chip inside. It has no effect on the physical keychain. NFCKEY is designed to IP68 ingress protection standards and features a self-repairing coating, so it remains durable regardless of how many times you reprogram it.