AI voice-clone scam calls: a UK guide for families and businesses
Share
Last checked: 25 October 2026
Short answer: Fraudsters can use AI to copy the voice of someone you know and then ask for money. Agree a safe phrase with close family and friends. If a call asking for money doesn't feel right, hang up and call back on a number you already know. At work, agree that nobody pays or changes bank details on the strength of a call alone.
What did Block announce?
On Friday 23 October, Block announced Dessa, a speech model built by a small AI research lab inside the company. Block describes it as "a true speech-to-speech model" that is "full-duplex, so it listens and talks at the same time".
It isn't available to the public. TechCrunch reported that "there is no public access to Dessa at the moment". Block's own page says it is "giving a small group of AI safety researchers early access".
Block hasn't said Dessa can copy a chosen voice. It says the model "picks what to say, when to say it and how, down to its own voice and personality". We're not suggesting Dessa has been used in any scam.
So why mention it? Because the recordings Block has shared are a sign of how natural computer-generated speech is starting to sound. That's a good prompt to set up a few simple checks at home and at work, while things are calm.
What is an AI voice-clone scam?
Report Fraud describes it like this: "Fraudsters use AI to generate fake audio clips (often known as AI voice cloning) impersonating the voice of someone you know or trust." They then ask for a payment.
Police Scotland gives a typical example: someone scamming a person you know "by pretending that you need money in an emergency".
The number on your screen isn't proof either. Report Fraud says fraudsters can change the number they call from so it shows up as one you know and trust. This is called number spoofing.
Step 1: agree a safe phrase with family and close friends
A safe phrase is a word or short phrase that only your close family and friends know. Report Fraud's advice is to agree one "to help you verify you are really speaking to them".
- Agree it face to face, not in a group chat or on social media. Report Fraud says to never share it outside your family or close friends.
- Make it something a stranger couldn't guess from your social media, so not a pet's name or a birthday.
- Use it. If someone calls claiming to be a family member or friend but can't tell you the safe phrase, Report Fraud says to hang up.
Police Scotland suggests the same idea: "think about having code words to use with loved ones if there's a real emergency".
To agree a family safe phrase and a "pause and check" plan with a parent, see our guide Helping an Older Relative Spot Scams.
Step 2: hang up and call back on a number you know
This applies whether the voice sounds like your son, your bank or your business partner.
- End the call. Ofcom says to hang up if you have any doubt about who is calling: "You can always call back."
- Call back on a number you already have. Use the person's usual number, or for an organisation, the number on its official website, a bill or the back of your card. Don't use a number the caller gave you.
- Take your time. Ofcom notes that "a genuine caller will always give you time".
- For your bank, call 159. Report Fraud says 159 gets you through to your bank.
Don't let a caller's knowledge of your details persuade you. Ofcom points out that scammers get personal information "from data breaches and public sources".
Step 3: a payment-check rule for your business
For a small business, the risk is a call that sounds like the boss, a regular supplier or a client asking for a payment or new bank details. A simple written rule helps everyone, especially the person who answers the phone.
Here's a rule you could adapt:
No payment, and no change to anyone's bank details, on the strength of a phone call, voice note or voicemail alone. Check it first on a second channel you already trust, such as a number you have on file, and not one given in the call or message.
A few things make the rule work:
- Confirm new or changed bank details directly with the company before you pay. Take Five, the UK anti-fraud campaign, says in its guidance on invoice and mandate fraud that "companies rarely change their bank details", so a change is always worth a query.
- Paying someone new? Send a small amount first and check with them directly that it arrived, as Take Five suggests.
- Make it fine to say no. Take Five's advice is that "it's ok to reject, refuse or ignore any requests". Tell staff that checking will never get them in trouble, even if the caller sounds like you.
If money has already gone, the NCSC says to contact your bank directly, using its official website or phone number.
For the wider basics in your business, start with our Small Business Cyber Starter Checklist.
Where to report a voice-clone scam call
- Report Fraud (formerly Action Fraud) is the national service for reporting fraud and cyber crime. Report online at reportfraud.police.uk or call 0300 123 2040.
- In Scotland, report to Police Scotland on 101.
- Scam calls on a mobile: text the word "Call" followed by the scam caller's number to 7726.
- If you've lost money, contact your bank straight away, using the number on the back of your card or, if your bank supports it, by calling 159.
Printable checklist: voice-clone scam calls
| Step | Who | Done? |
|---|---|---|
| Safe phrase agreed face to face | Family and close friends | ☐ |
| Known numbers saved for family, key staff, suppliers and your bank | Everyone | ☐ |
| 159 saved in your phone | Everyone | ☐ |
| Written rule: no payment or bank-detail change on a call alone | Business owner and anyone who pays bills | ☐ |
| Report Fraud number noted: 0300 123 2040 (Scotland: 101) | Everyone | ☐ |
Our Account Lockdown Kit, a paid guide we sell, covers the account and money side. It includes saving 159, calling a "friend" who messages from a new number asking for money on the number you already have, and a card of UK places to report scams. It doesn't cover safe phrases; that advice is all in this article. Get the Account Lockdown Kit
FAQ
What is a safe phrase?
A word or short phrase agreed with close family and friends, so you can check you're really speaking to them. Report Fraud recommends one.
Can you trust the caller ID?
No. Report Fraud says the caller ID display on your phone is "not proof of ID", because numbers can be spoofed.
Is Block's Dessa available to the public?
Not as of 25 October 2026. Block says a small group of AI safety researchers has early access.
What should a business do about voice-clone calls?
Agree a written rule that no payment or bank-detail change goes ahead on a call alone. Check it on a second channel you already trust.
Where do you report a voice-clone scam?
Report Fraud on 0300 123 2040 or reportfraud.police.uk. In Scotland, call Police Scotland on 101.
