Can a home door lock open with a phone?
Only with a lock built for it. The phone holds a credential that the lock system issued, so the question is never what a phone can do but what the lock accepts, and an industry standard for that conversation at the door is only now arriving.
A tag on the door is not a key
A tag is memory that answers anyone who powers it. A credential is a secret that proves itself without being handed over, held somewhere that will not disclose it, and issued by a party that decides who gets one. The car key page draws that line for vehicles and it holds for a front door.
So nothing written on a tag ever becomes a key, and a lock that opens for a tag has a different problem, which the credential page sets out for access systems generally.
What a phone can do is hold the credential, present it at the door, and refuse to present it until it has checked who is holding the phone. That is the whole of its contribution, and it is a large one.
The lock decides, not the phone
The credential has to be issued by whatever system the lock belongs to, provisioned into the device, and recognised by the reader. Today that usually means the lock manufacturer's own application and its own readers, with a phone key that works on their locks and nowhere else.
Putting the key in the platform wallet instead is a further step, and it needs an agreement between the lock maker and the platform. That is why a lock can support phones without its key appearing in a wallet.
Either way the lock is the gatekeeper. A phone that will not open a door is almost never a phone problem, which is the opposite of what the symptom looks like.
A standard for the door
Aliro, published by the Connectivity Standards Alliance, is a standardised communication protocol between access readers and user devices, defined by mobile and access control manufacturers together. Its stated aim is that manufacturer independent devices and readers work together at the door, with a certification programme behind it, and it covers residential as well as commercial installations.
What that changes for a buyer is the question to ask. Instead of whether a particular lock brand supports a particular phone brand, the question becomes whether both ends are certified to the same standard, which is the same shift that happened for wireless networking long ago.
Until the locks on the shelf carry it, expect the ecosystem answer: the lock works with the phones its maker has tested, and the list is theirs rather than the standard's.
The key that stays in a pocket
A door lock runs on batteries and keeps no connection, so it decides alone, like the validators the offline page describes. A key revoked on a server is not revoked at the door until something carries the news there.
The phone has its own failure mode: a flat battery presents nothing, and what survives one differs by device, which the phone off page covers.
Then there are the people a phone key does not serve: a visitor with an unsupported phone, a child, a cleaner, a neighbour watering plants. Every one of them is a reason the mechanical key or the keypad code stays in the design rather than being designed out.
Keep one physical way in, and keep it somewhere that does not depend on the lock's electronics being awake.
Frequently asked questions
Can I program my own tag to open a lock?
No. A lock that opens for a writable tag is not checking anything. A key is a credential issued by the lock system and held where applications cannot read it.
Why is my lock not in the phone wallet?
Putting a key in a platform wallet needs an agreement between the lock maker and the platform. Many locks support phones only through their own application.
What does Aliro change?
It is a standardised protocol between readers and user devices with a certification programme, so the question becomes whether both ends are certified rather than whether the brands match.
What if the phone is dead?
Nothing is presented. Keep a mechanical key or a code, and remember the lock itself runs on batteries that also fail.