The message lands at 8.50pm on a Tuesday. “Hi Mum, dropped my phone in the sink — this is my new number.” Denise, a school cook in Wolverhampton, smiles. Her son Jake is away at university in Leeds, and it sounds exactly like him. Twenty minutes later, “Jake” needs £480 for rent by morning. This is the WhatsApp hi mum scam, and it has taken millions of pounds from kind, careful parents across the UK. Here is how it works, the new AI twist, and the 60-second check that beats every version of it.
The “Hi Mum” Scam at a Glance
| What it is | A stranger poses as your child on WhatsApp or by text, then asks for money |
| The opening line | “New number” plus a lost, broken or water-damaged phone story |
| The ask | An urgent bill, rent or new phone, paid by bank transfer to an account you don’t know |
| Reported losses | £160,000 to “Hi Dad” scams by mid-June 2026 (Santander); £1.5m in one five-month spell in 2022 |
| The check | Ring the old saved number, ask a question only they’d know, use a family code word |
| If you paid | Call your bank via 159 at once; refunds of up to £85,000 under the APP rules |
| Report it | Block and report in WhatsApp; texts to 7726; Report Fraud 0300 123 2040 |
A Message From a Number You Don’t Know
Denise’s message followed a script that consumer group Which? has tracked since 2022, word for word: “Hello mum, I’ve broken my phone and I’m using a friends old one… can you text me on WhatsApp on my new number please.” Notice what’s missing. No name. The scammer sends the same opener to thousands of numbers and waits to see who replies “Jake, is that you?” — then plays whichever child you hand them. Between 3 February and 21 June 2022 alone, Action Fraud logged 1,235 reports of criminals posing as loved ones on WhatsApp, with £1.5m lost. The same script now arrives by ordinary text too, which is why it helps to know how to report a scam text the moment one lands.
Why It Fools Loving Parents
Students genuinely do drop phones in sinks, and that is the whole trick. The story is plausible, the tone is casual, and the pressure arrives only after you’ve relaxed. Santander’s fraud team found that sons are the most successfully impersonated relatives, followed by daughters, then mothers, and the bank reported £160,000 stolen through “Hi Dad” versions in the first half of 2026 alone. Action Fraud recorded a further £226,744 lost to “Hi Mum” and “Hi Dad” texts between 2023 and 2025. The rush matters more than the amount: the fraudster needs your transfer to land before you speak to your real child. It is the same trust-first playbook used in romance scams, just aimed at a parent’s heart instead of a partner’s.
The AI Voice-Note Twist
The scam’s nastiest upgrade is sound. Chris Ainsley, Santander UK’s head of fraud risk management, warned in 2025 that the con is “evolving at breakneck speed”, with AI voice impersonation now used to create WhatsApp and SMS voice notes that sound like the real person. Starling Bank’s research found criminals can clone a voice from as little as 3 seconds of audio lifted from a video posted online, that 28% of UK adults had been targeted within a year, and that 46% had never heard of the technique. So a voice note that sounds like your daughter proves nothing on its own. Criminals who pull off SIM swap fraud can even message from a number you trust, which makes the next check essential.
The 60-Second Check That Beats Every Version
Denise did the one thing scammers cannot survive. She rang Jake’s old number, the one saved in her phone for years. He answered mid-laundry, phone dry, rent paid. If the “lost phone” story were true, that call would go nowhere; if it rings, the scam is over. Back it up with a question a stranger could never answer — what you cooked last Sunday, the name of the first family dog — and never one answerable from Instagram. Better still, agree a family code word tonight and keep it off social media. A real child in a real fix will happily prove themselves. Only a fraudster argues with checking. And if you’ve already typed card numbers into the chat, treat it as if you gave a scammer your bank details and act fast.
Lock Your WhatsApp Before They Borrow It
Some “Hi Mum” messages come from a hijacked account rather than a strange number, so shore up your own. Open WhatsApp, then Settings, Account, Two-step verification, and set a six-digit PIN — a form of two-factor authentication that stops anyone re-registering your account on their phone. Never share that PIN, or the 6-digit code WhatsApp texts you, with anyone; WhatsApp itself never asks for them. Then go to Settings, Privacy, Calls and switch on Silence unknown callers, which mutes strangers’ calls but still lists them in the Calls tab. Set your profile photo, Last seen and Status to “My contacts” so scammers can’t harvest pictures and details. The official WhatsApp safety page walks through each setting with its Privacy Checkup.
Blocking and Reporting the Fake “Jake”
Once you know it’s a fraud, don’t reply with fury, tempting as it is. Open the chat, tap the name at the top, and choose Block and Report — that sends the most recent messages to WhatsApp so the number can be shut down. If the same con arrived as an ordinary text, forward it to 7726, the free spam-reporting number that works on all the main UK networks, and send a screenshot to report@phishing.gov.uk if you want the NCSC on the case too. Then warn the family group chat, because siblings and grandparents are usually next on the list. In banking language this con is a form of push payment fraud, and every report helps banks and networks spot the mule accounts behind it.
If the Money Has Already Gone
Sent the transfer before the doubt kicked in? Move quickly. Call your bank now — dial 159, the safe-dial service that connects you to 26 UK banks (call costs vary), or use the number on the back of your card. Faster Payments settle in seconds, so the sooner your bank knows, the better its chance of recovering funds. Since 7 October 2024, banks must refund most victims of authorised push payment fraud: up to £85,000 per claim, usually within 5 working days, minus an optional excess of up to £100. You have 13 months to claim, and being taken in by a convincing scam is not “gross negligence” — only around 2% of claims were refused for carelessness in early 2026. The full bank transfer scam refund rules are worth reading before you ring.
Tell Report Fraud — and Don’t Carry It Alone
One more call finishes the job properly. Report the crime to Report Fraud, the national service that replaced Action Fraud in January 2026, at reportfraud.police.uk any time or on 0300 123 2040, Monday to Friday 8am to 8pm; in Scotland, ring Police Scotland on 101. You’ll get a crime reference number, which supports your refund claim, and your report feeds the analysis that helps police link gangs together — here’s how Report Fraud works. Report it even if the bank repaid every penny. And if the episode has left you shaken, Victim Support’s free line, 0808 168 9111, is open 24 hours a day. With £576.4m lost to push payment scams in 2025, falling for one is common, not foolish.
What Denise Texted Back
Denise replied to the fake number with three words — “ring you now” — then called the real Jake and blocked the impostor before her tea went cold. That is the whole defence against the WhatsApp hi mum scam: slow down, check on a number you trust, and let the panic belong to the fraudster. Do one thing this week. Agree a family code word over Sunday dinner, save 159 in your contacts, and show this to the parent in your life most likely to say “but it sounded just like you”.
Frequently Asked Questions
What is the WhatsApp “Hi Mum” scam?
A fraudster messages from an unknown number pretending to be your child on a new phone, then asks for an urgent bank transfer for rent or bills.
What do hi mum scam messages usually say?
Typically “Hi Mum, I’ve broken my phone, this is my new number”, followed by an urgent money request and a “friend’s” account details. No name appears until you supply one.
Can scammers really clone my child’s voice?
Yes. Starling Bank found a voice can be cloned from about 3 seconds of online audio, so a convincing voice note alone proves nothing. Verify on the old number.
Can I get my money back after a hi mum scam?
Usually, yes. Bank transfers made on or after 7 October 2024 qualify for refunds up to £85,000 under the APP fraud rules, normally decided within 5 working days.
How do I report a hi mum scam number?
In WhatsApp, open the chat, tap the name and choose Block and Report. Forward text versions to 7726 free, and report losses to Report Fraud on 0300 123 2040.
Disclaimer: This article is general information, not financial or legal advice. Scam tactics, refund rules and contact details change, so check WhatsApp’s official safety pages, your bank and reportfraud.police.uk before acting. Figures are correct as of September 2026.