The only ongoing costs associated with AVT Sentinel™ are data and text charges made by Vodafone.

Data and text charges can be broken down into two broad categories:

• Charges incurred by Sentinel™ as part of its self-checking activities.

Periodically, Sentinel™ attempts to connect with its servers to check for software updates and to report how much credit is available on its SIM card. Information about the vehicle position is not included. These check-in messages cost about £3.65 per year. You will receive email alerts if the vehicle does not 'check in' for a certain number of days or if credit falls below a preset level. As well as emails, a text message can be sent to your phone if the situation persists.

• Charges as a result of using Sentinel™ to track your vehicle if stolen, or if the system needs to send a text message to alert you that the alarm has been triggered or the vehicle is moving unexpectedly. Remember that these charges only apply if the unit is being used to track the vehicle - i.e. the vehicle is stolen. They do not occur when the unit is in standby.

The Vodafone PAYG price plan currently allows 25MB of data per day for £0.50, with a minimum per connection billing of 5p. As the data that Sentinel™ sends is highly compressed, an entire day's tracking (sending updates every 10 seconds) is nowhere near this allowance. Therefore, in the UK the costs of tracking work out to around 30p per hour with a daily cap of £0.50.

When the vehicle is overseas, the cost is typically around 30p per hour of tracking. In some countries there is now a daily cap of £5, while other (typically non-EU) there is no daily cap.

Text messages from Sentinel™ to your phone are charged at 10p each when using the UK Vodafone network. In Europe, texts cost 11p - 49p depending on country. Most countries are now 11p as a result of an EU ruling on excess charging. Texts only occur if you request them, if the alarm is triggered, the battery is disconnected or unauthorised movement occurs.