NFC Tag

An NFC tag embeds a Near Field Communication chip that transfers data when a smartphone is held within about 10 cm. Passive tags require no power and last indefinitely. Like QR codes, NFC tags enable smartphone-based information retrieval, but with different technical characteristics and cost structures.

NFC's key advantage is no camera needed. Data reads automatically on tap, unaffected by lighting, rain, or gloves that challenge QR scanning. Assuming that NFC cannot be forged is a mistake. Most tags on the market keep their NDEF area writable, so reading the content and writing it to another tag yields one that behaves identically. Resistance to cloning requires tags that generate a single-use authentication code with an AES key on every tap and are verified server-side, such as NTAG 424 DNA.

However, NFC tags cost 30-100 yen each (vs under 1 yen for QR labels). They are unsuitable for mass distribution (flyers, packaging) but ideal for high-value products (luxury brands, pharmaceuticals) and reusable scenarios (access control, transit cards). QR codes and NFC tags are complementary, not competing technologies.

Two constraints are worth checking before rollout. The first is the surface. Metal behind a tag acts like a ground plane, detuning the antenna so the chip never receives the current it needs, which is why an ordinary tag stuck straight onto a metal can or housing will not read. Choose an on-metal tag with a ferrite layer shielding the metal, or leave a gap of a few millimetres up to about a centimetre. The second is the reading device. Background reading, where a tap responds without opening an app, is available on the iPhone XS and XR and later models (introduced with iOS 12); once the phone has been unlocked after a restart, it keeps scanning while the screen is lit, even when locked (reading while locked brings up a prompt to unlock before processing). Android devices also look for tags while unlocked, but not when NFC is switched off in Settings. Because the antenna sits in a different spot on each model, instructions that describe the motion, such as bringing the back of the phone slowly to the tag, work better than an icon alone. Before mass-producing tags, it also pays to test-read a few samples on the actual mounting surface, confirming the effects of material and device model in one pass; that is far cheaper than reworking after rollout.