Your phone rang once, maybe twice, and stopped before you could pick up. The screen shows a long number starting with +257, +855 or +234, and nobody left a voicemail. Most people who look these numbers up on UnknownDial have had exactly that call, often late at night or in the middle of the working day.
Who is calling from +257, +855 and +234?
These are international country codes. +257 is Burundi, +855 is Cambodia and +234 is Nigeria. A missed call from one of them, when you know nobody there, is almost always a one-ring scam known as wangiri. The word is Japanese and roughly means "one ring and cut".
The point of the call is to make you curious enough to ring back. Returning the call can be charged like a premium number, and the scammer gets a cut of what you pay. The Do Not Call Register's missed-call alert gives the same advice: don't call back.
What UnknownDial users report about these numbers
The most looked-up number on UnknownDial.com.au right now is +25731118658, with more than 200 comments. The reports are remarkably consistent. People describe the phone ringing for a second or two and then going dead, at all hours, with no message. One commenter in Western Australia logged a two-ring call just after midday. Another said they had been getting a run of calls beginning with +257, and some with 0257, over several weeks.
That last detail is worth noting. A number that starts with 0257 can look like a local 02 landline if you only glance at it, so read the whole number before you assume it's someone you know.
+85589932552 is another heavily searched number in a Cambodian mobile format. Many of the comments on its page aren't in English and don't describe a phone call at all, so there's not much first-hand detail. Treat a missed call from it the same way and leave it alone.
The Nigerian number +2349131195519 shows a different pattern. The one report on it describes a caller who claimed to be from New Zealand, offered no real service and kept asking for money for foreign investments. That sounds more like an investment pitch than a one-ring call, and it shows that a single country code can turn up in quite different schemes.
All of this comes from user reports. Caller ID can be faked, so the number on your screen doesn't prove who actually placed the call.
Is it dangerous to call back a missed international number?
The main risk is to your phone bill. If you ring back, you may be connected to a line that charges a high rate per minute, and whoever runs it may keep you on hold or play a recording to stretch the call out. Some people only notice when the bill arrives or their prepaid credit vanishes.
A missed call on its own can't get into your phone or take money from your bank account. The trouble starts when you return the call, answer questions or follow instructions from whoever picks up.
If you do have family, friends or business contacts overseas, ask them to text first or leave a voicemail. A real caller will usually try again or send a message. A one-ring scammer leaves nothing behind.
I already called back. What now?
- Hang up straight away if you're still on the line. The longer the call runs, the more it can cost.
- Check your call log for how long the call lasted and take a screenshot.
- Ring your telco, tell them you returned a one-ring call to an international number, and ask whether any premium or international charges have gone through. Ask whether they can be reversed.
- Keep an eye on your next bill or your prepaid balance for unfamiliar international charges.
- If the person who answered asked for personal details, banking information or a payment and you gave any of it, call your bank on the number on the back of your card. For help with identity theft, contact IDCARE on 1800 595 160.
If you only answered the original call and heard silence, there's usually nothing more to do than block the number.
How to stop missed calls from overseas numbers
Australian telcos already stop a large share of scam calls before they reach you. A Treasury release in May 2026 said telcos blocked around 109.9 million scam calls and 41.1 million scam SMS between October and December 2025. Some still slip through, especially from numbers that change every few days.
These steps cut down how many reach you:
- Block the number. On an iPhone, open the Phone app, go to Recents, tap the info button next to the number and choose Block Caller. On Android, press and hold the number in your call history and choose Block or Block/report spam, depending on the brand.
- Turn on unknown caller filtering. iPhones have a Silence Unknown Callers option in the Phone settings, and most Android phones have a spam filter in the Phone app's settings.
- Ask your telco about international call barring. If you never ring overseas, barring outgoing international calls means an accidental call-back simply won't connect.
- Don't reply by text or save the number. Any response can tell the scammer your number is live.
Where to report a wangiri call
You can report the call to Scamwatch on its report a scam page. Reports help authorities see which numbers and country codes are being used. The Do Not Call Register website explains missed-call scams in more detail, and the ACMA oversees the rules telcos follow when they block scam calls.
It also helps to leave a comment on the number's page. When you search the number on UnknownDial, add the time of the call, how many rings you heard and whether there was a message. That kind of detail lets the next person make up their mind in seconds.
Quick checklist after a one-ring call
- Leave unknown international numbers alone and don't ring back.
- Look the number up and read what others have reported.
- Block it on your phone and consider international call barring.
- If you did call back, contact your telco and check your bill.
- If you shared money or personal details, contact your bank and IDCARE.