Can one UniFi Access reader unlock two doors?

In UniFi Access, a door is a lock relay on an Access hub, and a reader(a keypad, a card reader, or a video door station like the G6 Entry family) is assigned to one door. The hub's documentation frames capacity strictly per door — one reader per door, or two readers on a single door when you want a reader on each side for entry and exit.¹ There is no setting that points one reader at two different doors, and no “linked doors” or interlock feature that fires a second door's relay from the first door's read.

That matters because every unlock method UniFi Access offers is read at a reader — tap an NFC fob on a reader, enter a PIN on a reader, present a face to a reader.² A reader belongs to one door, so the credential opens that one door.

A door does not need a reader, though. A door can be just a lock relay (plus an exit button or motion sensor for people leaving), and Ubiquiti documents that such a reader-less door can still be unlocked remotely through the Access application.¹ Hold onto that fact — it is what makes the “one credential, two doors” options later possible.

This is the part people are most often unsure about, and the answer is yes in both directions. A door station's doorbell call is configured with a list of receivers: you add the interior answering screens (UniFi calls them Intercom Viewers), and Ubiquiti's documentation lists those receivers in the plural and notes multiple notification methods can ring at once.³ Put every interior screen in the same call group and pressing the bell rings all of them together.

One detail worth getting right: receivers are organized into call groups that ring in sequence — a later group only rings if an earlier one goes unanswered.³ To make every screen ring at the same time, they all belong in the first group.

The reverse is also supported. A single Intercom Viewer can be a receiver for several door stations, so one screen can answer either entrance.⁴ And the Intercom Viewer is not tied to one model of door station — it answers calls from the G6 Entry family as well as the dedicated Intercom readers.⁴ The same doorbell press can also notify the UniFi mobile app, so a phone rings alongside the screens.³

When a call comes in, the answering screen shows a separate unlock control for each door it is associated with. So the package-versus-guest distinction is a matter of which button the person inside taps: the outer door alone for a courier, or the outer and then the inner for a guest. There is no single “open both” button — opening both is two taps — but functionally it does exactly what the scenario asks for: the inside person decides, per visit, how far in someone gets.

On the credential side, a current video door station such as the G6 Pro Entry reads the full set residents expect — an NFC card or keyfob, a PIN entered on its touchscreen, an Apple or Google Wallet phone tap, and face recognition.⁵ Each of those, read at that reader, opens that reader's door.

Here is where the rule from section 02 bites. A resident taps their fob at the outer reader and the outer door opens — but the inner door has its own relay, and the outer reader is not wired to it. UniFi Access has no native way to open two doors from one read. There are two honest ways to give a resident a clean walk-in, and they trade off differently.

Option one — a reader at each door. The inner door gets its own reader. The resident taps at the outer door, steps into the vestibule, and taps again at the inner door. Two taps. It is fully native, nothing custom runs anywhere, and a two-tap vestibule is the more secure arrangement anyway — a courier buzzed into the vestibule for a package cannot drift through the inner door, because the inner door needs its own valid credential.

Option two — a small automation.Keep the inner door as a reader-less relay and add a lightweight controller on the local network that watches the Access event stream. When it sees the outer door unlocked by a real credential, it calls Ubiquiti's official Access API to unlock the inner door as well — one tap, both doors.⁶ The API unlocks a single door by its ID, and each unlock event carries an authentication type (NFC, PIN code, or a doorbell call), so the automation can fire on a resident's credential and deliberately ignore a doorbell answer.⁶ That is what keeps “buzz open only the outer door for the courier” working even with the automation in place.

Both are real. The choice is whether a single-tap walk-in is worth running a small piece of custom automation — and the next two sections are the honest fine print on that.

The automation is built on Ubiquiti's published API, not a hack — but it is still a custom integration, not a feature you toggle on in the Access app. Two realities come with that.

It needs maintenance. The door-event path that the automation listens to has changed across UniFi Access firmware releases. An integration like this should be built against the stable event/webhook interface and re-tested after Access updates, not set up once and forgotten. Treat it as a small, owned piece of the system.

It must fail safe — and here is the trap. If the inner door is reader-less and the automation goes offline, a resident clears the outer door and then cannot get through the inner door, because a reader-less door has no on-door credential path and UniFi has no native fallback to open it.¹ They are not in danger — they can always turn around and exit to the street — but they cannot proceed inward. The fix is simple and worth stating plainly: keep a reader on the inner door even when you automate. Then the automation is a convenience layer on top of a system that already works on its own; if it ever drops, the entrance quietly falls back to the two-tap of option one and nobody is stranded.

Put differently: the reader-less shortcut looks cheaper, but it is the version that strands people. The automation is worth doing on top of readers, not instead of them.

Whichever option you pick, the safety question is always the same: can a person always get out? Getting out of a door is a hardware property, not a controller decision. A fail-safe lock unlocks when power is removed; a fail-secure lock stays locked without power.⁷ Free egress comes from a mechanical inside lever, a request-to-exit button, or a motion sensor that releases the lock for anyone leaving — none of which depend on the network, the cloud, or any automation.⁸

So an outage never traps anyone: egress hardware lets people leave regardless of what the electronics are doing. The thing an outage can break is entry— which is exactly why a reader on the inner door (section 06) matters. The detail to confirm on a real install is which doors a person passes through on the way out, and that each of those has code-compliant free egress; the lock's fail-safe-versus-fail-secure behavior is a building-code question for the local authority, not a UniFi setting.

None of this is exotic. A two-door entrance that rings every screen, lets the person inside choose how far a visitor gets, and gives residents a clean walk-in is a normal, buildable UniFi Access design — provided the one-reader-one-door rule is respected and the egress is sound. Specifying that correctly up front, down to which door gets a reader and how the low-voltage cabling is run, is the kind of work we design and install end to end.