Vodafone detects when you have subscribed to a chargeable service from the very first SMS you receive and, within the first 24 hours, sends you a free notification that includes the full details of the service you have subscribed to, the company that provides it, its cost, and how to deactivate it.

Each phone line has the ability to use any voice or SMS service. For example, every line can make international calls or send MMS messages; however, if you don’t use these services, you won’t be charged. The same applies to 5-digit SMS messages from third-party companies. The capability exists on your line, but if you don’t use or subscribe to any service, you won’t receive 5-digit SMS messages from third parties, so there are no unwanted charges.

The charge you incur depends on the third-party company and is based on the service you have subscribed to. Some services charge a one-time fee, while others have weekly or even monthly subscriptions.

If you want to activate a block on chargeable third-party services, read here.