Who called me? How to find out who's behind an unknown number

A missed call from a number you don't recognise is the most common way a scam starts - and also how your doctor, your courier and your kid's school get in touch. Here's how to tell which one it was, without calling back.

1. Look the number up on BadCall

Type the number exactly as it appeared - 0412 345 678, (02) 9876 5432, +61 412 345 678, 1300 123 456 or an overseas number. Each number has its own page showing:

• the BadCall Score - 0 (safe) to 100 (bad call) - from everyone's reports;
• what kind of call people say it is (scam, telemarketer, robocall, a real business...);
• who the caller claimed to be, in other people's words;
• the region for landlines, and the business that lists the number, if there is one;
• how many people looked it up recently - a spike usually means a campaign.

No reports yet? You may be early. Come back in a day, or add your own report so the next person isn't on their own.

2. Read the number itself

Australian numbers carry clues:

• 04xx - a mobile. It could be anywhere in Australia, on any network.
• (02) NSW/ACT, (03) VIC/TAS, (07) QLD, (08) SA/WA/NT - a landline, and the next digits narrow down the region (see number ranges).
• 1300 / 13 - a business number, popular with call centres. 1800 - freecall.
• + and a country code - an overseas call. A one-ring missed call from abroad is a classic wangiri scam.

3. Check if it's a real business

Search the number in quotes in a search engine. Many businesses list their numbers publicly - BadCall shows over 102,708 of them on the number pages. If it's a business you deal with, call them back on the number from their own website, not the one that rang you: caller ID can be faked.

4. Let it go to voicemail

A genuine caller leaves a message. Scam robocalls rarely do, or leave a recorded threat ("your tax file number has been suspended") - which is itself the answer.

5. Use your phone's built-in screening

iPhones can silence or screen unknown callers, and most Android phones label likely spam. See how to block and screen numbers.

6. Ask your provider

For repeated nuisance or threatening calls, your phone company can investigate and block them. For threats, contact the police on 131 444 (000 in an emergency).

7. Don't call back - unless you're sure

Found out who it was?

Tell everyone. Report the number - scam, genuine business, or anything in between. It's anonymous and takes 30 seconds.