Anatomy of a scam: the "Hi Mum, I've got a new number" text, line by line
A text from an unknown number says it's your son or daughter on a new phone — and they need money urgently. We take the "Hi Mum" family-impersonation scam apart message by message, and show the one check that ends it.
This is the third in our series taking a single scam apart, message by message. This one needs no special technology — no voice cloning, no deepfake — just a parent’s love and one well-placed lie. It’s the “Hi Mum” scam (also “Hi Dad”, “friend in need”, or WhatsApp family impersonation), and it has cost families millions. The ACCC reported over 1,150 Australian victims and $2.6 million lost in just seven months; Action Fraud in the UK tied £1.5 million in losses to the WhatsApp version.
Here’s how it unfolds. The exchange is invented, but every beat matches what the ACCC and Action Fraud describe.
The opener: a new number, pre-explained
Unknown number: Hi Mum, I dropped my phone down the toilet 😩 this is my new number, save it! x
Read that again, because the entire scam lives in one phrase: “this is my new number.” It explains, in advance, why the message isn’t coming from your child’s saved contact — the single fact that would otherwise give the game away. Before you’ve even wondered “why don’t I recognize this number?”, the scammer has answered it. The broken-phone detail is chosen because it’s mundane, a little funny, and instantly relatable.
Notice what’s not here: your child’s name. It’s just “Mum”. The message is deliberately generic so it works on anyone who receives it — the scammer is texting thousands of numbers and letting worried parents fill in the identity themselves.
The build: warm, brief, normal
Them: Phone’s being a nightmare, lost all my contacts. How are you anyway? x
A message or two of small talk establishes rapport and lowers your guard. There’s no ask yet — that patience is deliberate. You reply, maybe relieved, maybe a little rushed, and now a “conversation” is underway with someone you’ve already half-accepted is your child.
The pivot: an urgent bill they can’t pay
Them: Actually Mum I’m a bit stuck — I can’t log into my online banking on the new phone and I’ve got a bill due today. Could you pay it for me? I’ll sort you out tomorrow x
There it is. The ask is urgent, modest-sounding, and comes wrapped in a reason they can’t just do it themselves: they can’t access online banking on the new phone. The ACCC describes exactly this — victims are told the funds are needed because the sender “can’t access their online banking temporarily.” It’s the same logic as the new number: pre-explaining away the obvious question (“why can’t you pay it yourself?”).
The block: why they can’t just call
You: Let me call you quickly to check it’s you 😊
Them: Can’t talk right now, the speaker’s not working on this phone — can you just transfer it? I’m really stressed x
This is the most important exchange in the whole script, and it’s where you win. A real child will get on the phone. A scammer can’t — their voice won’t match — so the script always has an excuse ready. Action Fraud puts it plainly: when you try to call, “there’ll usually be an excuse why they can’t speak to you.” The refusal to take a simple call is the scam confessing.
How to spot it
The tells are in the box below, but the spine of the con is: an unknown number claiming to be family on a “new phone” + warm small talk + an urgent payment + a reason they can’t take a call. Each “pre-explained” detail (new number, no online banking, can’t talk) exists to defuse a question you’d otherwise ask. Notice the pattern and the whole thing falls open.
What to do instead
You don’t need to buy anything to beat this — the free move comes first (see the defense box). The strongest habit is a Family Safe Word: call the person on the number you already have saved, and if you reach them, the “new number” was fake. If you can’t reach them, ask a question only they could answer — that’s what a safe word is for. The voice-call version of “relative in trouble”, which adds an AI-cloned voice, is dissected in the AI family-emergency call. For more, see our defense moves and the 60-second quiz.
- A text or WhatsApp from an unknown number claims to be your child or close family on a "new" or "lost" phone.
- Within a few messages it turns to an urgent payment — a bill they can't pay because they "can't access online banking" on the new phone.
- They have a reason they can't take a call right now, and the money must go to a new account fast.
- Treat any "new number" message asking for money as a scam until you've verified it another way.
- Call the person on the number you already have saved. If they answer, the new-number message was fake.
- Ask a question only the real person could answer — your agreed family safe word is perfect for this.
- Never send money to a new account on the strength of a text alone, no matter how urgent it sounds.
There's no AI in this one — no cloned voice, no deepfake. It works on pure emotion and a single clever switch: by claiming a new number, the scammer pre-explains away the one thing that would catch them — that they're not really your kid's saved contact. That's the whole trick, hiding in 'I got a new phone.' So the move I'd hand any parent is almost insultingly simple: a 'new number' asking for money isn't a new number until you've called the old one. Ring the number you already have. If your child picks up, you've just caught a scammer.
Sources
Frequently asked
It really sounds like my child — same way of texting, knows my name. Could it be real?
A texting style and your name prove nothing — both can be guessed or pulled from social media, and the message is deliberately vague to fit anyone. The ACCC's advice is to verify independently: call the person on the number already stored in your phone, and if you can't reach them, ask a question a scammer couldn't answer. Don't rely on how the messages "feel".
Why can't they just hop on a call to prove it's them?
Because a call would expose the scam — the voice wouldn't match. So the script always includes a reason they can't talk: the new phone's microphone is broken, they're somewhere they can't speak, they'll call later. Action Fraud notes that when you try to call, "there'll usually be an excuse why they can't speak to you." That excuse is the tell.
I already sent money to the "new number". What should I do?
Contact your bank immediately — fast action gives the best chance of stopping or recovering a transfer, especially one not yet collected. Report it (in Australia via Scamwatch, in the UK to Action Fraud, in the US to the FTC and FBI IC3), and warn the family member being impersonated so they can alert their own contacts.