What Is an NFC Video Doorbell? Complete Guide

NFC — near-field communication — is the same short-range technology behind contactless payments and travel cards. A passive tag is a tiny antenna and chip with no power supply. When a phone with an NFC reader comes within a few centimetres, its field induces just enough current in the tag to power it long enough to transmit its stored data.

On a doorbell sign, that stored data is a single web address unique to that sign. There is no personal information on the tag, and the exchange is one-directional: the phone reads the tag, the tag learns nothing about the phone.

• A visitor holds the top of their phone against the marked area of the sign.
• The phone reads the tag and shows a notification with the link.
• Tapping the notification opens the call page in the browser.
• The browser asks for camera and microphone permission.
• The occupant's registered phone rings, and they see and hear the visitor.

The whole interaction typically takes a couple of seconds and needs no aiming, no focusing and no light — which is the practical advantage over scanning on a dark winter evening.

Neither method is reliable for one hundred per cent of visitors on its own. That is why DoorVi signs carry both.

Background tag reading — where the phone reacts simply by being held near the tag, with no app open — is supported on iPhone XS and later running current iOS, and on the large majority of Android phones sold in recent years. On Android, NFC can be turned off in system settings, and some budget models omit the hardware entirely.

Because you cannot know in advance what a courier or an unexpected caller is carrying, treating NFC as the fast path and QR as the universal path is the practical approach.

An NFC doorbell tag is a read-only pointer to a web page. It stores no phone number, no name, no credentials and no payment data, so there is nothing on it to steal. Its range of a few centimetres means it cannot be read in passing. Tapping the sign cannot install anything, cannot open a lock and cannot extract information from the visitor's phone.

The sign contains no camera and no microphone, so nothing is monitored at the door between calls. A call exists only when a visitor chooses to start one. In DoorVi's implementation the video is one way: the occupant sees the visitor, the visitor does not see the occupant or inside the property, and the occupant's number stays private.

Homes and flats

A tap is faster than a scan when someone is holding shopping or an umbrella — useful at any front door, and especially in flats where the alternative is a buzzer that may not work. See DoorVi for apartments and renters.

Deliveries

Couriers work to the second. Tapping a sign as they walk up is the lowest-friction way to reach an occupant before a parcel is marked as undelivered.

Business premises

At an unstaffed door, a tap reaches the right person directly instead of ringing a bell into an empty reception. See DoorVi for businesses.

DoorVi signs combine both technologies on one sign so the visitor can use whichever their phone supports. Both routes lead to the same secure browser-based call, both require nothing to be installed by the visitor, and neither requires power, wiring or batteries in the sign itself.