Look out for these...

• Prepaid tariffs. Normally more expensive than a contract, although prepaid plans can be a good value for those who primarily receive (and not make) calls. Be sure to keep a prepaid card filled, as providers generally charge about £35 to reconnect you to their network. Also watch for prepaid plans with expiration dates on the calling time.
  
  
• Analogue calling plans. These are being phased out in the UK. If you are currently on an analogue plan, consider switching as most providers currently offer good deals for switching to a GSM plan.
  
  
• Phone plans with lots of inclusive calls. For most users these are not cost-effective. These plans generally do not include calls to premium rate numbers, calls to other mobiles, overseas calls and calls to voice mail. You do however, burn up minutes when making calls during off-peak and weekend hours. Unless you make lots of calls during peak periods, you should normally select plans with the lowest number of inclusive minutes.
  
  
• Per minute billing. Most mobile calls are short. You will save money by picking a plan that calculates charges by the second.
  
  
• Roaming. It's expensive to make call from abroad. Roaming tariffs for each network are very complicated and vary a great deal from country to country. Be sure to check tariffs for countries to which you will be travelling frequently.
  
  
• Group plans. Some dealers offer better deals for multiple users. Centralised billing will also cut administration costs for your phones. Ask about this if you have multiple users in your company.