iOS Core NFC Programming Guide

iOS Core NFC Programming Guide

Apple introduced Core NFC in iOS 11 and has progressively expanded its capabilities with each major release. As of iOS 15, iPhones can read and write most NFC Forum tag types, though some restrictions remain compared to Android.

Core NFC Framework Overview

Core NFC is in the CoreNFC framework (import CoreNFC). The two primary session classes are:

Entitlement required: Add com.apple.developer.nfc.readersession.formats to your .entitlements file and configure the Privacy NFC Scan Usage Description in Info.plist.

<!-- Info.plist -->
<key>NFCReaderUsageDescription</key>
<string>Read NFC tags to verify product authenticity.</string>

NDEF Reading with NFCNDEFReaderSession

import CoreNFC

class NFCReader: NSObject, NFCNDEFReaderSessionDelegate {
    var session: NFCNDEFReaderSession?

    func beginScan() {
        session = NFCNDEFReaderSession(delegate: self, queue: nil, invalidateAfterFirstRead: false)
        session?.alertMessage = "Hold your iPhone near an NFC tag."
        session?.begin()
    }

    func readerSession(_ session: NFCNDEFReaderSession, didDetectNDEFs messages: [NFCNDEFMessage]) {
        for message in messages {
            for record in message.records {
                print("TNF: \(record.typeNameFormat.rawValue)")
                print("Payload: \(record.payload)")
            }
        }
    }

    func readerSession(_ session: NFCNDEFReaderSession, didInvalidateWithError error: Error) {
        print("Session invalidated: \(error.localizedDescription)")
    }
}

Tag Sessions and Writing

Writing requires NFCTagReaderSession (iOS 13+). The flow: detect tag → connect → cast to NFCNDEFTag → write message.

func readerSession(_ session: NFCTagReaderSession, didDetect tags: [NFCTag]) {
    guard let tag = tags.first else { return }
    session.connect(to: tag) { error in
        guard error == nil else { session.invalidate(errorMessage: "Connection failed."); return }
        if case let .miFare(mifareTag) = tag {
            // handle MIFARE / NTAG via NFCMiFareTag
        }
        guard case let .iso7816(iso7816Tag) = tag else { return }
        // send APDU commands for ISO 14443-4 tags
    }
}

For nfc-tag types compliant with NFC Forum (NTAG, MIFARE Ultralight), use the NFCNDEFTag protocol's writeNDEF(_:completionHandler:) after connecting via NFCTagReaderSession.

Tag Type Support Matrix

Limitations and Platform Differences

The most significant limitation: iOS does not support card-emulation-mode via HCE. Payment and transit card emulation requires Apple's NFC Express feature or a hardware secure element under Apple's control.

Use the NDEF Message Encoder to build test payloads and the NDEF Message Decoder to inspect tag content during development.

See also: Android NFC Programming Guide and Web NFC API Guide.