Which iPhones can read NFC tags?
Two lines matter rather than one. There is a model line below which tag reading does not happen at all, and a second, higher line above which it happens without opening an application. Most confusion about iPhone NFC comes from treating those as the same line.
Two lines, not one
The first question is whether a model can read a tag at all, through an application. The second is whether it can notice a tag on its own, without anything being opened.
These are different capabilities with different thresholds, and the second is the higher one. A phone can be perfectly capable of reading tags and still do nothing when you wave one at the lock screen.
Almost every complaint about iPhone NFC dissolves once these two are separated.
Reading through an application
An application asks the system to read a tag, the system takes over the interaction, and the result is handed back. Apple documents this through Core NFC.
This is the reliable path on every model that supports tag reading at all, and it is the only path on the older ones.
Take NFC Tools. On iOS it requires an iPhone 7 or later running iOS 15.6 or later, and the app must be launched manually. Background reading is available from the iPhone XS and XR onwards.
That statement is worth reading twice, because it contains both thresholds: the model and version required to read at all, and the higher model line for reading without opening anything.
Reading without an application
Background reading is available from the iPhone XS and XR onwards. On earlier supported models an application has to be launched manually before a tag can be read.
So a person with an older supported iPhone, waving it at a tag on a poster, gets nothing at all. Their phone is not faulty and the tag is not faulty.
For a public deployment this is the single most important fact about iPhone support, because it decides what proportion of visitors succeed without instruction.
Checking a specific model
Find the exact model rather than the marketing name, in the settings under the heading about the device.
Then test with a tag you know works. Open a reading application first, since that is the path available on every supporting model, and only then try it from the lock screen. Two results, two answers.
That test takes a minute and settles the question for that phone more reliably than any list.
Frequently asked questions
Can every iPhone with NFC read tags?
Not every model that has NFC hardware for payment reads tags for you. Reading tags and paying are different modes with different requirements.
Why does my iPhone do nothing at a poster?
Background reading is available from the iPhone XS and XR onwards. On earlier supported models an application has to be launched manually.
Do I need to install anything?
On models with background reading, no. On earlier supported models an application is required, and it must be opened before the tap.
How do I find my exact model?
In the settings, under the heading about the device. The marketing name is not precise enough, since variants differ.