SwiftUI NFC Reader with a Bottom Sheet Result

An NFC reader on iOS is simpler and more constrained than people expect. Core NFC scans NDEF tags, and the system presents its own scan sheet while it listens. Your interface job is what happens around that: a clean SwiftUI bottom sheet that shows the scanned result, offers a retry, and points to the next action. VP0 is the free, AI-readable iOS design library builders use as the visual starting point for that sheet, so you can focus on wiring Core NFC instead of designing from scratch.

Who this is for

You are building a SwiftUI app that scans NFC tags on posters, products, stickers, or access points, and you want a native result sheet plus the correct entitlements. This is the pattern, and the honest limits.

Core NFC reads tags, not cards

The single most important truth: Core NFC reads tags, it does not read payment cards. Apple’s Core NFC documentation covers NDEF messages and several tag technologies, but the EMV data on a credit card is off limits. Accepting an in-person card tap is Tap to Pay on iPhone, a separate capability that needs an approved payment-platform SDK and a special entitlement, the same boundary covered in our Core NFC and Tap to Pay guide. Decide which one you actually need before writing code, because they share a name and almost nothing else.

What Core NFC can and cannot do

Capability	Core NFC	Note
Read NDEF tags	Yes	Posters, stickers, products
Write NDEF tags	Yes	Encode a URL or text to a blank tag
Background tag reading	Yes on iPhone XS and newer	A tap opens your app, no session needed
Read payment cards	No	That is Tap to Pay, a separate entitlement
Work on Simulator	No	Requires a physical iPhone 7 or newer

Background tag reading is a quiet superpower: on iPhone XS and later, tapping a tag can launch your app through a URL without any session UI at all.

Wiring the scan and the sheet

Start an NFCNDEFReaderSession when the user taps Scan. iOS shows its system scan sheet; you cannot fully theme that part. When a tag is read, dismiss the system sheet and present your own SwiftUI bottom sheet with presentationDetents so the result slides up at a comfortable height. Show the decoded payload, a clear success or error state, and a retry button. This is the same native-sheet discipline used in a Bluetooth pairing flow, where the connection states drive the UI.

Set up the entitlement

Two pieces of setup trip everyone up. First, add the Near Field Communication Tag Reading capability in Xcode, which writes the entitlement. Second, add an NFCReaderUsageDescription string to Info.plist explaining why you scan, or the session fails without an obvious error. The global NFC market is projected to pass $30 billion in the coming years, and most of that is tag reading like this, not payments. Once the capability and usage string are in place, the system scan sheet appears on a real device.

A worked example: scan a poster

Say you put an NFC sticker on an event poster. The user taps Scan in your app, the system scan sheet appears, and they hold the phone near the sticker. Core NFC reads the NDEF record, which holds a URL, and your app dismisses the system sheet and slides up the result bottom sheet showing the event name and a View details button. If the read fails, the sheet shows a friendly retry instead of an error code. For a hands-free version, encode the same URL so iPhone XS and newer launch your app on a background tap, with no in-app Scan button required. The reading code is a few dozen lines; the polish lives entirely in that result sheet. Field-service apps often scan an asset tag like this and then generate paperwork such as a plumbing invoice.

Common mistakes and fixes

• Expecting to read a credit card. Use Tap to Pay for payments; Core NFC is for tags.
• Missing the usage description. Add NFCReaderUsageDescription or the session silently fails.
• Testing on Simulator. Core NFC needs a physical iPhone 7 or newer.
• Theming the system scan sheet. You cannot; put your branding in the result bottom sheet instead.
• Ignoring write mode. You can encode a URL onto a blank tag, useful for a LiDAR-style scan-to-info flow.

Key takeaways

• Core NFC reads and writes NDEF tags; it never reads payment cards.
• The system owns the scan sheet; your SwiftUI bottom sheet owns the result.
• Enable the NFC capability and add NFCReaderUsageDescription, or scanning fails.
• Test on a physical iPhone 7 or newer, and start from a free VP0 design.

Frequently asked questions

The FAQ above answers where to get a free template, whether Core NFC can read cards, what setup NFC needs, and why a scan fails to start.