Signal Linked Devices: One Number, Five Extra Screens, and the Rule That Protects You
Signal's Android app can now link a second Android phone or tablet to an account that is already registered on a primary phone. The distinction that matters is registration versus linking: one number is registered to one phone, and everything else attaches to that registration as a secondary device, capped at five.
That single sentence prevents the most common and most destructive mistake - installing Signal on a new phone and registering the number there, which moves the account and can leave the old device signed out. Linking is the correct path when you want a second device, not a replacement.
What the limits actually are
| Device role | What it can do | Limit | What it cannot do |
|---|---|---|---|
| Primary phone | Register the number, send and receive, manage linked devices | One per account | Coexist with another registered phone on the same number |
| Linked Android phone | Send and receive through the account, with its own session | Counts toward the five secondary devices | Become the primary without re-registering |
| Linked Android tablet | Same as a linked phone, on a larger screen | Counts toward the five | Register a number of its own |
| Desktop, iPad, iPhone | Link to the account as a secondary device | Counts toward the five | Act as primary for an Android registration |
| Removed device | Nothing - its session keys are revoked | Re-linking requires a new QR scan | Read messages after removal |
The last row is the security feature worth knowing about. Removing a linked device from the primary phone invalidates its session, so a lost tablet stops receiving messages the moment you remove it rather than when you remember to change a password.
Linking a device without breaking anything
Step 1 Confirm which phone is primary
On the phone that currently receives your Signal messages, open Settings and check Linked Devices. That list is the authoritative answer, and it is the device you must keep.
Step 2 Install Signal on the second device without registering
Open the app and choose the linking option rather than entering your number. Entering the number starts a registration, which is the path that moves the account.
Step 3 Scan the code from the primary phone
On the primary, choose Link New Device and scan the QR code shown on the second device. Both devices need a network connection for this step.
Step 4 Expect new messages, not a clone
A newly linked device joins the account going forward. Whether older conversations appear depends on the sync the app performs, so treat the primary as the archive and do not uninstall it before verifying on the new device.
Step 5 Name the device
Give it a recognisable name when prompted. A list of five identically named entries is how people remove the wrong device months later.
Step 6 Review the list and remove what you do not use
Prune old tablets and work laptops from Linked Devices. Each one is a live session that can read every new message.
Rules that prevent the usual disasters
- Never register your number on a second phone to "test" it; that moves the account off the first device.
- Keep the primary phone until you have confirmed the new setup works, especially before a factory reset.
- Turn off message notifications on a shared linked tablet, or the previews appear on a screen others use.
- Do not back up Signal with a generic phone-transfer tool and expect a restore to work; its database is tied to the device keys.
- Remove a lost device from the primary rather than waiting for the number to be re-registered.
- Do not rely on a screenshot of a conversation as a backup; export is a deliberate action the app provides.
Does linking a device copy my chat history?
Not as a full clone. A linked device joins the account and receives messages from that point, and the app's sync behaviour determines how much recent history appears. Verify on the new device before you remove the old one.
Can I use Signal on two phones with one number?
You can link a second phone as a secondary device, which is the supported route. What you cannot do is register the same number twice - the second registration takes the account away from the first.
What happens if I lose the primary phone?
You re-register the number on a new phone and re-link the secondary devices. Messages that existed only on the lost device are gone unless you had exported them, because the encryption keys lived there.
Is a linked device less secure?
It is a full participant in the conversation with its own session keys, so its security is the security of that device. That is the reason to keep the list short and remove anything you no longer use.
💡Protip:
Chat history is the part that does not follow you to a new phone by itself. Dr.Fone - Phone Transfer can help move messages, contacts and photos between devices you own.
🔍More Info:
1. Google Messages Backup and Restore, Explained2. Chat Backup and Restore Across Messaging Apps
3. What End-to-End Encryption Does and Does Not Protect
4. Reading a Message Backup You Already Have
