Calls that ring once and hang up: the wangiri scam

Calls that ring once and hang up: the wangiri scam

Your cellphone rings once, you look at the screen and the call has already ended. The number is unknown, sometimes with a strange country code you do not recognise. Your first impulse is to call back: what if it was important? That impulse is exactly what the person on the other end wants. This is the missed-call scam, known as wangiri (Japanese for "one ring and cut"), and it has worked for years because it plays on the most basic curiosity.

How wangiri works

The method is simple, which is why it works:

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 do not know. Many of these numbers carry unusual international codes (+216 Tunisia, +234 Nigeria, +355 Albania, +675 Papua New Guinea...). South African numbers start with +27, or with a single 0 when written the local way, so any other country code means the call comes from abroad.
3. If you call back, you are connected to a premium-rate number: recordings that 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. On prepaid, it comes straight off your airtime; on contract, the bill arrives weeks later, when it is hard to claim anything back.

There is also a version that is not after the cost of the call but wants to confirm your number: by calling back, you show that your line is active and that a real person answers, and your number becomes more valuable on the lists sold to telemarketers and scammers. It is the same goal as calls that hang up as soon as you answer, except that here you are the one making contact.

The signs that give it away

• One ring, then nothing. Genuine callers let it ring; wangiri needs you NOT to answer, so it cuts the call on purpose.
• An unknown international code. If you are not expecting calls from abroad, a code you do not recognise is reason enough not to call back.
• Odd hours. Many batches go out late at night or early in the morning, when you are least likely to answer and most likely to find a missed call when you wake up.
• Repeats in waves. If you get several similar missed calls within a few days, it is an active campaign, not a coincidence. In the spam numbers directory you can see which numbers other people are reporting.

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

The right response fits in three steps:

1. Do not call back. If it were important, they would call again or leave a message. No bank, government office or serious company works by ringing once and hanging up.
2. Check the number before you do anything. Look it up in the spam numbers directory: wangiri reuses numbers for days, and usually dozens of people have already reported it. If you are not sure whether a number is South African, our dialling code guide shows the local prefixes.
3. Block and report. If you confirm it is wangiri, your report turns your missed call into a warning for the next person.

And what not to do: do not call "just to see who it was", not even for one minute out of curiosity. One minute on a premium-rate number is enough to be charged, and the recording is designed to stop you from hanging up quickly.

Can I be charged for a call I did not answer?

No. Receiving a call and not answering it never costs you anything, whatever country it comes from. The wangiri risk is only in calling back. In the same way, answering one of these calls in time does not cost you anything while you are in South Africa (the caller pays); the danger starts if they ask you to call another number "to continue". That is the same trap with an extra step.

Quick questions

What if I called back without knowing? Hang up as soon as you suspect it, check how long the call lasted and contact your network (Vodacom, MTN, Cell C, Telkom or whichever you use) to ask about the cost and whether they can block international or premium-rate calls on your line. If you have already been charged, complain to your network in writing and, if they do not resolve it, take it to ICASA, the communications regulator, though a refund is not guaranteed. If you lost a large amount, you can also open a case at your nearest police station (SAPS).

Does blocking the number help? Against that specific number, yes. But campaigns keep changing numbers, so blocking only goes so far: the real protection is the habit of never returning unknown missed calls with strange codes.

Does this only happen on cellphones? No, it reaches landlines too. If older people at home use a landline, it is worth leaving a note next to the phone: "missed call from a strange number = do not call back". You will find more advice on our blog.

If you have 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.