How to set up a safe phrase to stop AI scam calls

If you have read the news lately, you have probably seen the advice: agree a “safe phrase” with your family so you can check that an urgent phone call is really from who it claims to be. Banks and fraud-prevention campaigns are now recommending it, because AI can clone a loved one’s voice from just a few seconds of audio. This guide explains what a safe phrase is, how to set one up, and the common mistakes that quietly make a safe phrase useless when you need it most.

What is a safe phrase?

A safe phrase is a secret word or short phrase, known only to a small group of trusted people, used to confirm someone’s identity over the phone. If a caller sounds exactly like your daughter, your mum or your boss and is pressing you to act fast, you ask for the safe phrase. If they cannot give it, you know not to trust the call, no matter how convincing the voice sounds.

It works because it does not rely on recognising a voice or a phone number, both of which can now be faked. It relies on a shared secret that a scammer has no way to know.

Why banks and the police now recommend one

Voice cloning used to be science fiction. It is not anymore. Free and cheap tools can copy a person’s voice from a short clip scraped off social media or a voicemail greeting. Scammers use the cloned voice to call a family member with a panicked story: an accident, an arrest, a phone that broke, and an urgent need to send money right now.

The usual defences fail against this. The number can be spoofed to look familiar. The voice sounds real. The pressure is deliberate, designed to stop you thinking. A safe phrase cuts through all of it with a single question that an impostor cannot answer.

How to set up a safe phrase

1. Choose who is in your group. Start with the people most likely to be impersonated or targeted: parents, grandparents, children, and anyone who would wire money if a relative seemed to be in trouble.
2. Agree the phrase together, in person or on a call you are certain is genuine. Never send it by text or email, where it could be read by someone else.
3. Make it memorable but not guessable. Avoid pet names, birthdays, street names or anything that could be found on social media.
4. Agree how it will be used. The rule is simple: any urgent or money-related call must pass the safe phrase, every time, no exceptions.
5. Practise once. A quick dry run makes sure everyone remembers it and is comfortable asking for it, even from someone they love.

The three mistakes that make a safe phrase fail

A safe phrase you set up yourself is far better than nothing. But a single fixed word has three weak spots, and a scammer only needs one of them.

• It gets forgotten when it matters. The one moment you need the phrase, a frightening call about a loved one, is the worst possible moment to recall a word you agreed months ago and have never used.
• Once it leaks, it leaks forever. If the phrase is ever overheard, guessed or phished out of someone, it is compromised for good, and most families never get around to changing it.
• It does not scale. Agreeing one word across a whole family, keeping everyone on the same one, and updating it regularly, is the kind of admin that rarely happens in practice.

How to make a safe phrase foolproof

The fix for all three problems is the same: stop relying on a single word that someone has to remember and that never changes.

That is the idea behind SafePhrase. Instead of one fixed word, everyone in your group sees the same three-word phrase on their own phone, and it automatically changes every 60 seconds. There is nothing to memorise, because your phone always shows the current phrase. An overheard phrase is useless moments later, because it has already changed. And it works across the whole family with no ongoing effort, because every phone stays in sync on its own.

Crucially, the phrase is calculated privately on each device from a shared secret. It is never sent to or stored on any server, so there is nothing to intercept or leak. It even works with no signal.

The bottom line

Agreeing a safe phrase is genuinely good advice, and if you do nothing else, do that. But if you want it to actually work in the moment a scammer calls, you want a phrase nobody has to remember, that cannot be reused once overheard, and that keeps your whole family in sync automatically. That is the difference between a safe word and SafePhrase.