What button do I press to let someone in on an apartment intercom?

It depends on your intercom type. If the intercom dials your cell phone, press 9 on the phone dialpad during the call, or 6 if 9 does nothing. If you have an old-style wall handset inside your apartment, pick it up and press the door or key button on the unit itself. The release is set by the building's hardware, so whichever one clicks the door open is yours from then on.

How do I know if my intercom rings my phone or a handset on the wall?

Have someone select your unit at the entrance panel. If your cell phone rings, it is a telephone-entry or call-box intercom that dials out. If instead a box on your apartment wall chimes and you talk through it, it is a hardwired handset intercom that never leaves the building. The two are used and troubleshot completely differently.

What happens if I miss the intercom call to my phone?

On a phone-dialing intercom the door only releases while you are on the live call, so a missed call or one that goes to voicemail cannot be opened after the fact. The visitor just re-selects your unit and your phone rings again. There is no separate button that opens the door later, which is why a muted or unanswered phone leaves someone stuck until they ring again.

Can the intercom reach more than one phone so any of us can answer?

By default a call-box intercom dials a single number per unit, so only that one phone rings. To reach several phones you need call forwarding to a group line or an app that rings everyone on the account at once. That is the usual fix for roommates and couples who do not want entry to hinge on one person being reachable.

Blog / How to Use an Apartment Intercom (and Let Someone In)

How to Use an Apartment Intercom (and Let Someone In)

By Ty · 2026-07-16

You just moved into an apartment with an intercom, someone is coming over, and you realize you do not actually know how it works. Does your phone ring? Is there a code? What are you supposed to press? It is simpler than it looks once you know which of the two common intercom types you have, because letting someone in works differently on each.

First, figure out which intercom you have

When a visitor finds your name or unit on the panel by the front door and presses call, one of two things happens:

It calls your phone. Most modern apartment intercoms are really a call box that dials out. Your phone rings from the building’s number, you answer, and you press a key to open the lobby door. This is the same system Canadians call a buzzer.
A handset on your wall chimes. Older buildings use a hardwired intercom box mounted inside your unit. You pick it up, hear the visitor, and press a door button on the box itself. Nothing leaves the building and no phone is involved.

How to let someone in

If it dials your phone:

Your phone rings from an unknown number. The call comes from the building’s line, not a saved contact, so it shows up as a number you do not recognize. That is normal. Answer it and you can talk to whoever is at the door.
Press the door-release key. While you are on the call, press the key that unlocks the front door on your phone dialpad. On most systems it is 9. Some use 6, so if 9 does nothing, try 6 while still connected. Whichever one clicks the door open is your building’s key from then on.
Your visitor comes up. The intercom only opens the building’s front door, so they still come up to your unit and knock.

If it is a wall handset: lift the handset when it chimes, talk to confirm who it is, and press the door or key symbol on the unit to release the lobby door. If there are two buttons, one is usually talk and one is the door; a quick test with a friend tells you which.

Two things worth doing early: save the building’s calling number as a contact so a phone-based intercom never goes to voicemail or gets flagged as spam, and learn your release key before anyone is waiting by dialing your own unit from the panel and trying 9 then 6.

Where Lowkey helps

If catching the intercom call in time is the hard part, Lowkey presses the button for you. It answers the intercom call through your phone and opens the building’s front door so your visitor can come up, either automatically or when they enter a 4-digit passcode on the keypad. A muted phone, a meeting, or a phone in the other room never strands someone in the lobby again.

Any roommate or family member on the account can let people in from their own phone, so it never matters whose number the intercom happens to call. You get a push notification when someone is let in and an activity history of every entry, on 99.99% uptime, and the 14 day trial lets you try it on your own panel first. (It works with intercoms that dial out to a phone number, not standalone wall handsets that never place a call.)