NFC vs ultra wideband
Ultra wideband measures distance and direction precisely, at ranges of metres, which is what makes item finders and hands free car keys work. NFC identifies one object you deliberately touched. They answer different questions and are increasingly used together rather than instead of each other.
Two different questions
Ultra wideband works by timing very short radio pulses, which lets two devices calculate how far apart they are with far more precision than signal strength ever allowed. Some implementations also derive direction.
So UWB answers "where is it, and how far". NFC answers "which one am I touching". Neither can do the other's job, and framing them as competitors misses what each is for.
Car keys, where both appear
Digital car keys are the clearest example of the two coexisting in one product.
UWB lets the car know the phone is approaching, and crucially where it is: outside the door rather than inside the cabin, which matters for deciding whether to unlock or to allow the engine to start. Distance measured by timing is much harder to spoof than distance inferred from signal strength, which is why the industry moved to it.
NFC provides the deliberate fallback. Holding the phone against a specific spot on the door handle works when the hands free path does not, and it is the mechanism that keeps working in the situations where a broadcast approach is unreliable. The Car Connectivity Consortium, which specifies digital keys, states that NFC support is maintained for backward compatibility and for battery low mode.
Finding things
UWB item finders let a phone point you towards a tracker across a room, which no NFC device can do at any price. This is the use case that put UWB in consumer hardware.
The cost is the same one BLE pays: the tracker is an electronic device with a battery and a service life. Attaching one to every object you own is not economical, which is why trackers are for the few things you actually lose rather than for inventory.
An NFC tag on the same object costs cents and tells you nothing until you find it yourself. That is a genuine limitation and it is also why tagging a hundred items with NFC is reasonable and tagging a hundred items with UWB is not.
Which to specify
If you need to know where something is without touching it, only UWB does that, and you are accepting a battery in every tracked object.
If you need to identify an object at the moment someone touches it, NFC, at a fraction of the cost and with no maintenance.
If you are building a product where a user approaches, then acts, both may earn their place: UWB for the approach, NFC for the deliberate confirmation. That is exactly the pattern the car industry settled on, and it generalises.
UWB hardware is also far from universal across handsets, which for a public facing deployment is usually decisive on its own.
Frequently asked questions
Do all phones have ultra wideband?
No. It appears on higher end models and is absent from much of the market, which rules it out for anything the general public must be able to use. NFC hardware is far more widespread.
Can UWB replace NFC for payments?
Not today. The payment ecosystem is built on the contactless card interface, and the deliberate short range exchange is a feature of that design rather than an inconvenience to be removed.
Is UWB more accurate than Bluetooth for distance?
Substantially, because it measures the time a pulse takes to travel rather than inferring distance from how strong a signal appears. Signal strength is affected by obstacles and orientation, which makes it unreliable for anything needing precision.
Why do car keys still include an NFC fallback?
Because a deliberate touch at a known spot is a robust last resort when a hands free mechanism does not engage. The fallback needs to work in the conditions where the convenient path fails.