Why is my NFC tag not working?
Three questions asked in order isolate almost every fault. Does this phone read any tag at all. Does this tag read on any other phone. And does the tag hold the content you think it holds. Each answer eliminates a whole family of causes.
Ask three questions in order
Does this phone read any tag? Try a different tag you know works. If nothing reads, the problem is the phone or its settings, and the tag is innocent.
Does this tag read on any other phone? Try a second device. If it reads there, the first phone or the way it was presented is the variable.
Does the tag hold what you think? Read it with a tool that shows the content and the technical data. A tag can be perfectly readable and hold nothing an operating system knows how to act on.
Answering these three before changing anything saves most of the time people spend on NFC faults. Almost every question in this section is a branch off one of them.
Three families of cause
| Family | Typical signs | First check |
|---|---|---|
| The phone | No tag reads at all, or only some do | NFC enabled, case removed, antenna located |
| The tag | Reads nowhere, or only at contact | Compare with a known good tag |
| The content | Detected but nothing runs, or the wrong thing | Read the records and their types |
The environment cuts across all three. Metal, another tag, a wireless charger and a thick case each produce symptoms that look like a faulty tag and are not.
The diagnostic kit
A tag you know works, kept aside and never deployed. It is the single most useful thing to own, because it turns a guess into a comparison.
A second phone, ideally an older one. Faults hide on good hardware.
A reading tool that reports technical data rather than only acting on content, so you can see the tag type, the free space and the records.
A note of where each phone's antenna sits. Half the reports of an unreliable tag are a phone held in the wrong place.
Mistakes that waste an afternoon
Changing two things at once. Replace the tag or move the phone, not both, or the result tells you nothing.
Testing on the best phone available. The margin that hides a fault is exactly the margin your visitors will not have.
Assuming a tag is faulty because it does nothing. Detection and action are different steps, and a tag can be read perfectly while holding content the phone has no handler for.
Trying to rewrite a tag that is locked. Locking is permanent, and no amount of retrying changes it.
And working on an installed tag. Take one off the wall and test it on a bench, where you control everything.
All guides in this section
- Nothing happens on tap
- Read distance problems
- Metal and environment
- Locked or protected tags
- Phone side problems
- Writing failures
Nothing happens on tap
- Nothing happens when I tap the tag: where to start
- A brand new tag does not respond at all
- The phone vibrates but nothing opens
- The tag is detected but no action runs
- The tag reads but opens the wrong thing
- The tag works on one phone but not another
- My tag only works sometimes
- My tag stopped working after a while
- The tag works in the app but not from the lock screen
Read distance problems
- My tag only reads when touching: is that normal?
- Read distance dropped after installation
- One tag in a batch reads much worse than the others
- The tag reads on one side of the phone only
- I cannot find the right spot on my phone
- Reading works standing still but not in passing
- Reads get worse when the battery is low
- Two identical phones give different read distances
Metal and environment
- My tag stopped working once stuck on metal
- The tag fails inside a car
- The tag fails on a fridge or an appliance
- My tag fails outdoors in cold weather
- The tag stopped working after getting wet
- Another tag nearby breaks the read
- The tag fails near a wireless charger
- The tag fails behind glass or a screen protector
Locked or protected tags
- I locked my tag by mistake: what now?
- The tag says read only and I did not lock it
- I forgot the password I set on a tag
- A pre encoded tag cannot be rewritten
- Writing fails with a protection error
- How do I know if a tag is locked before writing?
- The tag is not locked but still refuses writing
- The tag accepts writing but the content disappears
Phone side problems
- My phone does not detect any tag
- Does my phone even have NFC?
- Is NFC enabled? How to check on Android and iPhone
- NFC disappeared from my phone settings
- NFC stopped working after a system update
- NFC works after a restart, then fails again
- My iPhone does not read tags automatically
- NFC works for payment but not for tags
- My phone reads tags but cannot write them
Writing failures
- Writing fails halfway through
- The message is too large for the tag
- The URL is truncated after writing
- The tag opens a search instead of my site
- Writing succeeds but the action does not trigger
- A URL writes fine but Wi-Fi or a contact fails
- Accented characters come back wrong after writing
- Writing corrupted the tag
Frequently asked questions
Where should I start if nothing works at all?
With a different tag on the same phone. That one test separates a phone problem from a tag problem in seconds, and everything else follows from the answer.
How do I know if my phone is the problem?
If a tag you know works also fails on it, the phone or its settings are the variable. Check NFC is enabled, remove the case, and find the antenna.
My tag reads but nothing opens. Is it broken?
No. Reading and acting are separate steps, so a readable tag can hold empty or unactionable content, and from Android 17 a web link waits for the user to act on a notification. Read the records to see what is actually on it.
Can a tag be repaired?
Physical damage to the antenna and permanent locking are both unrecoverable. Most other faults are configuration or environment rather than damage.