SPAM is the official term for unsolicited, non-chargeable text messages used by companies as a form of advertising. They often include a premium rate number to call or text back.

So if you or your child is receiving nuisance SPAM text messages, the best thing to do (unless you're sure it's a genuine message) is to not respond. Instead, you should forward the SPAM text to us on 7726.

If the message seems like a scam (like win a holiday or cash prize) then it will usually have a response phone number to ring. In this instance, O2 can bar the number to prevent any further customers from losing money by dialling it. In more complicated cases, we'll investigate the message by consulting the specialists at our Nuisance Call Bureau - and take the necessary further action to prevent any more costs or damage.

We also work with PhonepayPlus (the premium rate regulator) to help protect children and other customers from SPAM texts.

• To report SPAM to O2, forward anything suspicious to 7726
• PhonepayPlus: http://www.phonepayplus.org.uk/

How to STOP unwanted subscription texts

Sometimes when customers find that they've signed up to an unwanted premium rate subscription. For example, we often hear from parents whose children have signed up to a new ringtone service - the result being that they end up unwittingly paying out for the service each month.

Services like these are easy to cancel. To stop unwanted subscription texts, text STOP to the sender.

More about our work on helping keep children safe when using their mobiles.