How to Use an Encrypted Messenger Without a SIM Card
Yes, you can run an encrypted messenger without a SIM card. Here's how to message securely on Wi-Fi-only tablets, deregistered phones, and de-Googled devices.
By The PrivacyPortal Team
You can absolutely use an encrypted messenger without a SIM card — a Wi-Fi-only tablet, an old phone you've taken the SIM out of, or a de-Googled device is all you need. The catch is that most mainstream apps still tie your identity to a phone number at sign-up, even if you never plan to send a single text over the cellular network. This guide explains which apps actually work SIM-less, why a phone number and a SIM card are two different problems, and why an on-device identity is the cleanest fit for a SIM-free setup.
SIM card vs. phone number: two different things
It's worth separating two ideas that get blurred together.
- A SIM card connects a device to a mobile carrier. It's what lets you make cellular calls and send SMS, and it ties a physical device to a subscriber account.
- A phone number is an identifier. Many messengers use it as your username and require an SMS or voice code to prove you control it.
You can have one without the other. A Wi-Fi-only tablet has no SIM and no number. A deregistered phone might have a number that no longer receives texts. And a de-Googled Android phone might have a working SIM but no way to run Google-dependent apps. Each of these is a "SIM-less" scenario in practice, and each one breaks a slightly different assumption that messaging apps make.
Which encrypted messengers work without a SIM card?
The real question is: does the app need a phone number to register? If it does, you'll need access to some number to receive a one-time code, even if the device itself has no SIM. If it doesn't, the whole problem disappears.
| Messenger | Phone number to register? | Runs on a Wi-Fi-only device? | Identity type |
|---|---|---|---|
| Signal | Yes (SMS/voice code) | Yes, as a linked device | Phone number |
| Yes | Yes, via companion linking | Phone number | |
| Telegram | Yes | Yes | Phone number (usernames optional) |
| Session | No | Yes | Random account ID |
| Threema | No (optional) | Yes | Threema ID (paid app) |
| Graphite | No | Yes | 12-word recovery phrase |
A few honest notes on this table. Signal is a genuinely private, well-audited app, and once it's set up you can link it to a tablet or desktop over Wi-Fi with no SIM at all. But registration still requires a phone number and an SMS or call to verify it, so a truly number-free start isn't possible. WhatsApp and Telegram are the same in this respect — the number is the account. Session and Threema were designed to skip the phone number entirely, which makes them naturally SIM-friendly. Graphite sits in that second group.
The "linked device" workaround
If you're set on Signal or WhatsApp for a Wi-Fi-only tablet, the linked-device (companion) mode is the standard path: register on a phone that can receive a code, then link the tablet. It works well, but it means your identity is still anchored to that original number and the phone that holds it. For a genuinely SIM-independent identity, an app that never asks for a number in the first place is simpler and more durable.
Why an on-device identity is ideal for a SIM-free setup
When there's no SIM, a phone-number identity is working against you. An identity that lives on the device itself sidesteps the whole issue.
Graphite uses this model. Instead of a phone number or an email address, your identity is a 12-word recovery phrase generated on your device. There is no account on the server to register, verify, or recover through a carrier. That has a few practical consequences for SIM-less devices:
- Nothing to verify. No SMS code means a Wi-Fi-only tablet or a deregistered phone can onboard with no cellular access whatsoever.
- Portable identity. Because the phrase is the account, you can restore the same identity on another device without a number, a SIM swap, or a carrier.
- No number to leak. There's no phone number attached to your profile for anyone to look up or link back to you.
For the deeper trade-offs of dropping the phone number entirely, see our pillar guide to the encrypted messenger landscape, and our roundup of the best encrypted messenger with no phone number.
Running it on the devices you actually have
Here's how a SIM-less setup maps to real hardware.
A Wi-Fi-only tablet
A tablet with no cellular radio is the classic case. Graphite runs as a web app and — for Android tablets — as a sideloaded APK, so you don't need a SIM, a number, or the app store. Everything routes over Wi-Fi.
A deregistered or "retired" phone
An old handset with the SIM removed makes a solid secondary messaging device. Because Graphite's identity is a recovery phrase rather than a number, that retired phone becomes a first-class device rather than a second-class "linked" one.
A de-Googled or GrapheneOS phone
Privacy-focused Android setups often have no Google Play Services at all, which quietly breaks apps that depend on Google's push or licensing. Graphite's Android build is a sideloaded APK that works on GrapheneOS and de-Googled phones with no Google services present — a common pairing with a SIM-less or data-only configuration.
What "encrypted" should actually mean here
Working without a SIM is only half the goal; the messages still need to be genuinely private. A few things worth checking in any app you pick:
- End-to-end encryption by default, so the server never sees plaintext. Graphite uses NaCl/libsodium X25519 sealed boxes, with a hybrid post-quantum layer (ML-KEM-768) and forward secrecy via a Signal-style double ratchet.
- Network-level privacy. A SIM-less device still has an IP address. Graphite routes signaling and messages over Tor by default, fail-closed (a bundled Tor connection to a hidden service), which hides your IP and network. One nuance to be accurate about: real-time call media is peer-to-peer DTLS-SRTP, not carried over Tor — but on mobile, calls are routed so the other person doesn't see your IP.
- A relay that keeps nothing. Graphite's relay stores only sealed ciphertext, with a 7-day maximum TTL, deleted after delivery. It never sees your plaintext, your keys, or your recovery phrase.
You also get encrypted voice and video calls (DTLS-SRTP), encrypted group chats and file sharing, and on-device AI message search where nothing is uploaded — all without a SIM in sight.
Quick recap
- A SIM card and a phone number are separate requirements; SIM-less messaging usually fails on the number, not the SIM.
- Signal, WhatsApp, and Telegram run fine on Wi-Fi-only devices but still need a phone number to register.
- Session, Threema, and Graphite skip the phone number, which makes them a natural fit for tablets, deregistered phones, and de-Googled devices.
- An on-device identity — like Graphite's 12-word recovery phrase — removes the last dependency on a carrier or a number.
If you want a step-by-step comparison focused on the number specifically, read our Signal alternative without a phone number guide next.
Try Graphite. It's a free, public beta encrypted messenger for Windows (portable .exe with bundled Tor) and Android (sideloadable APK, GrapheneOS-friendly) with no phone number, no email, and no logs — built for exactly the SIM-less setups above. Download it at https://graphite.chat.