We have different world zones to simplify overseas call and data charges – which means you don't have to remember call costs for each individual country.

The world zones differ slightly depending on what type of contract you're on and which Bolt On you’re using – see world zones here.

It's always free to receive a text on O2 Business when you’re overseas.

Calls cost more abroad because O2 Business has to pay for customers to use international networks, which is above and beyond your usual tariff payments.

Voicemail is generally set up to divert calls when you're on the phone, out of range, or when your handset is switched off. In the UK these diverts are free of charge, but if you don’t answer a call when you're abroad, the foreign network sets up another call to the UK.

This is the additional call. We're working to solve this issue, however if you're concerned about this, we would strongly recommend setting up 'divert all' for calls to voicemail so you’re not charged. To do this while you’re overseas, you can use Voicemail 901.

Accidental roaming occurs when you're in an area close to a national border and your phone picks up the network across the border. If this happens, you may be charged as though you were roaming in the country across the border. You can prevent this by choosing manual rather than automatic network selection on your handset. Then, manually select the O2 network. This way, if you lose the O2 network, your handset won't try to connect you to a different one

Voicemail 901 lets you hear your messages overseas.

To set it up:

• Call 1750 to switch on your voicemail
• Call 1780 (+447802 090 100 outside the UK) to get your Voicemail Retrieval Number (VRN)
• We'll send a text with your VRN
• Dial your VRN to get your voicemail - you'll be charged the same rate as a call to the UK

In some countries you'll hear your own personal greeting.
If this happens:

• Key * then your Voicemail 901 four-digit pin (the default pin is 8705)
• Press 2 to hear your messages

Callers can leave messages directly in your mailbox by dialling your VRN - they'll only be charged for a UK call.
To divert all calls to Voicemail 901:

• Use your mobile's menu or
• Key *21*901# and send

To cancel, key ##21# and send.

All calls made abroad are shown on your bill under Roamed calls, and include the network you called from.

We try to show overseas call charges on your next bill, but sometimes there may be a delay.