Mobile phone scams can be difficult to recognize. Be wary of somebody who talks as if they know you or of redialling a missed call from an unknown number - there may be hidden charges.

Ringtone scams might attract you with an offer of a free or low-cost ringtone. What you may not realize is that by accepting the offer, you may actually be subscribing to a service that will keep sending you ringtones - and charging you a premium rate for them. There are many legitimate companies selling ringtones, but there are also scammers who will try to hide the true cost of taking up the offer.

Scammers either don’t tell you that your request for the first ringtone is actually a subscription to a ringtone service, or it may be obscured in fine print related to the offer. They also make it difficult for you to stop the service. You have to actively "opt out" of the service to stop the ringtones and the associated charges.

Missed call scams start by scammers calling your phone and hanging up so quickly that you can’t answer the call in time. Your phone registers a missed call and you probably won’t recognize the number. You may be tempted to call the number to find out who called you. If it is a scam, you will be paying premium rates for the call without knowing.

Text message scams work in a similar way, but through a Short Message Service (SMS). Scammers send you a text message from a number you may not recognize, but it sounds like it is from a friend - for instance: "Hi, it’s John. I’m back! When are you free to catch up?" If you reply out of curiosity, you might be charged at premium rate for SMS messages (sometimes as much as $4 for each message sent and/or received).

An SMS contest or SMS trivia scam usually arrives as a text message or in an advertisement and encourages you to take part in a trivia contest for a great prize. All you need to do is answer a certain number of questions correctly. The scammers make money by charging extremely high rates for the messages you send and any further messages they send to you. With trivia scams, the first set of questions will be very easy. This is meant to encourage you to keep playing. However, the last one or two questions that you need to answer to claim your "prize" could be very difficult or impossible to answer correctly.

Protect yourself:

• Text "STOP" to end unwanted text messages or to end unwanted subscriptions.
  
  
• Never reply to text messages offering you free ringtones or missed calls from numbers that you do not recognize.
  
  
• Don’t call or text phone numbers with are beginning with the well-known digits of premium phone numbers unless you are aware of the cost involved and carefully read any terms and conditions when texting short codes.
  
  
• Read all the terms and conditions of an offer very carefully. Services offering free or very cheap products often have hidden costs.
  
  
• Ask yourself if you know how to stop any subscription service I want to sign up to?