Signal wants to make phone numbers optional without giving spammers a free pass

Signal is finally letting people sign up without handing over their phone numbers, but it’ll cost $3. The option is rolling out in the Android 8.28 beta, removing a longstanding registration requirement for people who’d rather keep their phone numbers private.

It’s a one-time payment, not a subscription. Signal says the fee is meant to discourage spammers from creating accounts in bulk, while its payment system prevents purchases from being directly linked to the accounts they create.

Why is Signal charging for privacy

Removing the phone number requirement could make it easier for spammers to create accounts at scale. Charging for each registration makes that considerably more expensive without forcing people to provide a phone number. Signal has also introduced separate protections against phishing and fraudulent profiles.

The fee is $3 in the US, although prices may differ by country. Registering with a phone number remains free, so existing users aren’t suddenly being asked to pay for Signal.

Signal also hasn’t committed to keeping the price at $3. If numberless accounts become a significant source of spam, the company may increase the fee to discourage mass registration.

How does Signal keep payments private

Paying for an account introduces an awkward privacy question. A purchase could potentially create a link between someone’s payment information and the account they’re trying to keep separate from their identity.

Signal uses the same zero-knowledge proof system behind its donations to prevent that connection. The company can process the purchase without directly associating it with the resulting account.

Payment anonymity is only one aspect of privacy, though. Notification previews can still expose Signal messages through a device’s operating system, depending on its settings.

There’s a catch for anyone using an Android device without Google Play Services. Payments currently go through Google Play, so those devices aren’t supported. Signal plans to introduce additional payment methods, although it hasn’t provided a timeline.

What should users know before signing up

Numberless accounts come with a strict recovery system. Signal provides an Account ID and Account Key, and losing either means permanently losing access. There’s no recovery mechanism, so saving both in a password manager is essential.

Existing users can’t remove phone numbers from their accounts yet, either. Anyone hoping to switch an existing account to the new system will have to wait while Signal considers whether to support that option.

For additional protection, Signal also offers a built-in screen lock and other privacy controls, although these won’t help recover a lost Account ID or Account Key.