This will look a little bit different when you check your account usage while roaming. Technically you will have 2-3 call charges appear in your usage. For example:
1st charge (where applicable ) - If you are travelling outside of an EU Zone 1 Country you will be charged when someone leaves you a voicemail. To cancel all diverts dial ##002# and press the ‘call’ button on your phone.
2nd charge (where applicable): When you listen to the voicemail left.
3rd charge: If you return the call through voicemail or call catcher. If you returned the call through our ‘call catcher’ service the number ‘08557111111’ will appear in your usage.