I checked the datasheet linked in his description. It also has an inductance of 1.4uH, although I take your point the tuning will help. Do you think an antenna that small will even be able to be detected by a phone (its only 15mm/15mm). I will have another go with capacitors and get back to you. Are you sure theres nothing else I need to do on the software side. I’ve seen bits and pieces about making sure the pins are enabled for nfc, and not configured as standard gpio pins.
Thanks again