How To Program An NFC Keychain With Your Smartphone
NFCKEY allows you to program NFC interactions like links, contact cards, WiFi credentials and more. This means that you can write your contact information, website, or social media links directly onto the chip using a smartphone.
We recommend using the NXP® TagWriter app, available on both Android and iOS.
Before you begin, ensure the chip type you have is phone programmable. Here are some examples NFCKEY offers:
- NXP NTAG® 213 – 144 bytes
- NXP NTAG® 215 – 504 bytes
- NXP NTAG® 216 – 888 bytes
If you are not sure what type of NFCKEY you own, download the NXP® TagInfo app and scan the keychain.
Quick guide
Follow these steps to get started
1
Download the NXP® TagWriter App
Download the app to your device and ensure your phone has NFC enabled.
2
Decide What Type Of Data You Want To Upload
Prepare the type of data you want to appear when NFCKEY is tapped on a device.
3
Enter Your Information and Save it
Input the chosen data into the app and save it.
4
Write The Data To Your NFCKEY
Tap “Save & Write” and hold the NFCKEY near your phone until confirmed.
5
Test Your NFCKEY
Tap NFCKEY to your phone to confirm the data opens correctly. Make changes if needed.
6
Edit Information (If Necessary)
Edit your saved data anytime through the app’s “My Datasets” section.
Step 1: Download the NXP® TagWriter App
The NFC TagWriter app by NXP® allows writing tags, adding business cards, storing contacts, bookmarks, pairing with Wi-Fi, or Bluetooth®, enabling hotspots, sending text messages and much more all with just a tap.
Learn more about the app here
Download on Android: [Download Here]
Download on iOS: [Download Here]
Tip: Prior to the encryption process, make sure your phone has NFC enabled in the settings.
Step 3: Enter Your Information and Save it
After you have chosen the type of record you want to add, input all the necessary information into the app.
To add the website link:
1. Add the 'Description' and 'URI data' that you want to appear when NFCKEY is tapped on a supporting device
In our case, we will be adding data for our website (https://www.nfckey.com/).
2. Double-check the spelling to ensure all details are accurate
3. Press ‘Save & Write’
If your records saved successfully, you will see the screen as below, specifying the type of record and its weightage.
Step 4: Write Data To Your NFCKEY
After you successfully added the necessary information into the app, it's time to write it on to the NFCKEY.
1. Press 'Save & Write' again
2. Hold your NFCKEY close to the phone’s NFC sensor (the sensor is typically on the back panel of the phone, right next to the camera)
3. Wait for confirmation that writing is complete
Tip: Make sure the chip is not near metal surfaces while writing as it may interfere with the signal.
Step 5: Test Your NFCKEY
Once you have written the chosen information on the NFC keychain, check it's 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 6. If not, you are done!
Remember: You can rewrite the information on your wearable anywhere and anytime using the app and the NFCKEY.
In our case, the link has been saved successfully and it appears on the phone screen when NFCKEY is tapped on the phone.
And you’re done!
Step 6 (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 app's Main Menu
2. Click the 'My Datasets' section
3. Pick the dataset you want to edit
4. Click 'Edit'
5. Input the new information, repeating Steps 3-5
Check Out How Else NFCKEY Can Be Used
Frequently Asked Questions
Does NFCKEY work with iPhone and Android?
Yes. NFCKEY works with NFC-enabled iPhones (iPhone XS and newer) and most Android devices that support NFC.
Make sure NFC is enabled in your phone settings before scanning.
Where is the NFC sensor located on my phone?
- iPhone: Top back area, near the camera.
- Android: Usually on the back center (location may vary by model).
Hold the NFCKEY close to that area for 1–2 seconds.
Why isn’t my NFCKEY scanning?
Common causes:
- NFC is turned off
- The phone is not positioned correctly
- The chip is too far from the sensor
- The tag is near metal, which interferes with signal
- The tag has been permanently locked
Try repositioning the keychain and ensuring NFC is enabled.
Can I rewrite my NFCKEY after programming it?
Yes. NFCKEY can be rewritten multiple times unless it has been permanently locked.
Simply repeat the writing steps in the app to update the information (Step 3-5).
How much data can NFCKEY store?
Storage depends on the chip type:
- NTAG® 213 – 144 usable bytes (ideal for links and short text)
- NTAG® 215 – 504 usable bytes (larger contact cards and more data)
- NTAG® 216 – 888 usable bytes (maximum storage capacity)
For most website links and standard contact cards, NTAG® 213 is sufficient.
Why does the app say “NDEF record already exists”?
This means the NFCKEY already contains stored data. You can overwrite it by writing new information to the tag (follow the instructions in Step 6)
What does “Lock Tag” mean?
Locking a tag makes the data permanent. Once locked, the information cannot be edited or erased.
Only lock your NFCKEY if you are certain the data will not need to change.
