Calls that ring once and hang up: the wangiri scam

Calls that ring once and hang up: the wangiri scam

Your phone rings once, you look at the screen and the call has already ended. The number is unknown, sometimes with a strange international code you don't recognise. Your first instinct is to call back: what if it was something important? That instinct is exactly what the person on the other end is after. It's the missed-call scam, known as wangiri (Japanese for "one ring and cut"), and it has worked for years because it exploits the most basic curiosity.

How wangiri works

The mechanics are simple, which is why they work:

1. An automated system calls thousands of numbers and hangs up after one or two rings, before you can answer.
2. You see a missed call from a number you don't know. Many of these numbers carry unusual international codes (+216 Tunisia, +234 Nigeria, +355 Albania, +675 Papua New Guinea...).
3. If you call back, you're connected to a premium-rate number: recordings designed to keep you on the line as long as possible (surveys, prizes, recorded messages) while the meter runs.
4. The cost per minute is high and part of it goes to the scammer. The bill arrives weeks later, when there's little left that's easy to claim back.

In New Zealand, premium-rate numbers start with 0900, but wangiri normally uses overseas numbers, so don't assume a call is safe to return just because it doesn't start with 0900.

There's also a version that isn't after the cost of the call but confirming your number: by calling back you prove your line is active and that a real person responds, and your number becomes more valuable on the lists sold to telemarketers and scammers. It's the same goal as silent and hang-up calls (see our situation guides), except here you're the one making contact.

The signs that give it away

• One ring and gone. Legitimate callers keep ringing; wangiri needs you NOT to answer, so it's programmed to cut off.
• An unknown international code. If you're not expecting calls from overseas, a code you don't recognise (anything other than +64, New Zealand's own) is reason enough not to call back.
• Odd hours. Many batches go out in the middle of the night or first thing in the morning, when you're likely not to answer and to see a missed call when you wake up.
• Repeated waves. If you get several similar missed calls within a few days, it's an active campaign, not a coincidence. In the spam numbers directory you can see whether other people are reporting the same numbers.

What to do (and not do) about a suspicious missed call

The right response fits in three steps:

1. Don't call back. If it were important, they'd call again or leave a message. No bank, government agency or reputable company works by ringing once and hanging up.
2. Check the number before doing anything. Look it up in the spam numbers directory: wangiri reuses numbers for days, and usually dozens of people have already reported them, with the code and the trick identified.
3. Block and report. If you confirm it's wangiri, your report turns your missed call into a warning for the next person.

It's the "Stop, Check, Report" habit that Consumer Protection's Scamwatch recommends for any scam, and scams can also be reported to the National Cyber Security Centre (NCSC).

And what not to do: don't call "just to see who it was", not even out of a minute's curiosity. One minute on a premium-rate number is enough to be charged, and the recording is designed to stop you hanging up straight away.

Can I be charged for a call I didn't answer?

No. Receiving a call and not answering it never costs you anything, whichever country it comes from. The wangiri risk is only in calling back. Likewise, answering one of these calls in time doesn't cost you anything either (the caller pays); the danger starts if they ask you to call another number "to continue". That's the same trap with an extra step.

Quick questions

What if I've already called back without realising? Hang up as soon as you're suspicious, check how long the call lasted and contact your provider (One NZ, Spark, 2degrees or whoever you're with) to ask about the cost and about barring international or 0900 premium-rate calls on your line. If you've already been charged, complain in writing, and if your provider doesn't resolve it, you can take it to Telecommunications Dispute Resolution (TDR), the industry scheme for unresolved telco complaints. Be aware that a refund isn't guaranteed.

Does blocking the number help? Against that particular number, yes. But campaigns rotate numbers, so blocking only goes so far: the real protection is the habit of not returning unknown missed calls with strange codes.

Does this only happen on mobiles? No, it reaches landlines too, especially in the afternoon. If older people at home use a landline, leave a note by the phone: "Missed call from a strange number = don't call back." You'll find more advice on the NoCall blog.

If you've had one of these missed calls, look it up in NoCall's spam numbers directory and report it: every report helps the next person who sees that number on their screen know not to call back.