"Hi Mum, it's me. Dropped my phone down the loo, this is my new number. Can you save it? x" A few messages later: "Really awkward but my banking app won't work on the new phone and my rent is due today. Could you send £780 and I'll pay you back tomorrow?"
Reading it cold, it looks obvious. Receiving it on a busy afternoon, from someone who writes just like your child, it doesn't. The "Hi Mum" scam - also sent as "Hi Dad" - has been one of the most widely reported messaging scams in the UK for several years, with banks including Santander and Barclays warning customers about it.
Our position is that spotting the fake message is the wrong goal. Scammers keep improving the message. The only reliable defence is to check through a channel the scammer doesn't control: the number you already have, or a question only your family can answer.
How the script works, step by step
Almost every version follows the same stages. Recognising the stage you are in is more useful than judging the wording.
- The opener. A message from an unknown number: "Hi Mum" or "Hi Dad", often with no name. You fill in the name yourself, which is exactly the point.
- The explanation. A lost, broken or stolen phone explains the new number and why they can't call.
- The small talk. A few friendly messages to build normality. Some scammers now send voice notes.
- The problem. A bill, rent, a new phone or an overdue payment that must be sorted today.
- The block. Their banking app "doesn't work on the new phone", so they need you to pay for them.
- The payee. Money must go to an account in a name you don't recognise - "my friend's account" or "the landlord's".
- The repeat. If the first payment works, another request follows.
Why intelligent people fall for it
Here's the thing: this scam isn't aimed at people who don't understand technology. It is aimed at parents who love their children and are used to helping them. Being asked for money by a grown-up child is completely normal in many families, and so is a smashed phone.
It also exploits a very British reluctance to seem suspicious of your own family. Asking "is this really you?" can feel rude. Scammers rely on that awkwardness far more than on any technical trick.
Voice notes make it harder. There have been reports of scammers using AI tools to imitate voices in voice messages. A short, slightly muffled clip of "Mum, it's me, just send it please" can remove the last doubt. We don't think you should try to judge whether a voice is cloned - you'll lose that contest eventually. Use a check that doesn't depend on the voice at all.
The checks that actually work, ranked
| Check | How well it works | Why |
|---|---|---|
| Call your child on the number you already have | Best | A lost phone is usually findable, switched on or reachable by someone with them |
| Ask the family code word or a private question | Very good | The scammer can copy writing style, not shared memories |
| Ask them to call you from the new number | Good | Most scammers avoid live calls, though voice cloning makes this less certain |
| Contact their partner, flatmate or another relative | Good | Confirms the story independently |
| Judge the spelling, tone or emojis | Poor | Scammers adapt, and real children text badly too |
If you only do one thing, call the old number. It takes thirty seconds, and in most cases your actual child answers, puzzled, from a perfectly working phone.
Set up a family code word now
A code word sounds dramatic, but it is the most practical fix we know for impersonation scams of every kind, including fake calls with cloned voices. Agree it face to face, not by text:
- Pick a word or phrase nobody would guess from social media - not a pet's name or a street you lived on.
- Agree that anyone asking for money in an unusual way will be asked for it, and that asking isn't an insult.
- Share it with grandparents and older relatives, who are frequent targets.
- Never send the code word in a message; say it only on a call you started.
Alternatively, agree on a simple rule: "we never ask each other for money by text from a new number". A rule is easier to remember than a word.
What to do if you've received the message
- Don't reply with personal details or the name you think they are - it helps the scammer.
- Call your child on their known number.
- If it's a scam, report and block the number in WhatsApp (open the chat, tap the contact name, choose Block and report) or, for an ordinary text, forward it to 7726.
- Look up the number on Who Rang to see whether others have had the same message.
- Warn the rest of the family - scammers often try several relatives.
If you've already sent money
Act quickly. Call your bank straight away using 159 or the number on your card and tell them it was a scam payment. Banks can sometimes stop or recover transfers if they are told fast, and since October 2024 banks and payment firms must reimburse most victims of authorised push payment scams, subject to the rules and limits in force.
Then report it. In England, Wales and Northern Ireland, report to Report Fraud, which replaced Action Fraud. In Scotland, call Police Scotland on 101. Keep screenshots of the conversation and the account details you paid.
Don't be embarrassed. The scam is designed around love and trust, not stupidity, and people who report it quickly give their bank the best chance of helping.
The same "urgent problem, act now" pattern shows up in other scams using official names. If a message claims to be from the taxman rather than your family, see our guide to HMRC scam calls and texts.
Frequently asked questions
What is the Hi Mum scam?
A scammer messages you from an unknown number pretending to be your child with a new phone, then asks you to pay an urgent bill or send money to an account in someone else's name.
Does the Hi Mum scam only happen on WhatsApp?
No. It started mainly on WhatsApp but also arrives by ordinary text message, and some versions use voice notes.
Can I get my money back after a Hi Mum scam?
Contact your bank immediately. Many victims of authorised push payment scams are entitled to reimbursement, but speed helps, so call 159 or the number on your card straight away.
How do I check if it's really my child?
Call them on the number you already have, or ask a question only they could answer. Don't rely on how the messages are written or how a voice note sounds.
The bottom line
The "Hi Mum" message will keep getting more convincing, so don't make your safety depend on spotting it. Make it depend on a habit instead: any request for money from a new number gets checked on the old number or with a family code word, every time. Thirty seconds of awkwardness is the whole price of beating this scam.