The Apple iOS NFC SDK, CoreNFC, only supports reading an NFC tag if it has been properly encoded.
If you are using an iPhone NFC App and an NFC tag is not being detected, it is very likely that the NFC tag is not NDEF encoded.
Encoding Requirements
The following requirements must be met for an NFC tag to be properly read by iOS:
- NDEF encoded. If the NFC tag is empty or has not been NDEF formatted or is encoded with an alternate data format, iOS will not be able to read the NFC tag.
- At least 1 NDEF record; multiple NDEF records are supported.
- All NFC Forum NFC tag types, 1-5 are supported