We need to take the thai work phone to europe to keep in contact with our staff. We will mostly use LINE (if possible) and / or WhatsApp. Also will need to log onto KTB online banking and get the OTP code. 

 

To avoid huge fees on return do I need to 

1. call dtac and enable international roaming? do I only do this right before getting on the plane?

2. in europe... turn off data roaming? do I then connect to wifi?

 

Finally, we were given a free samsung smart phone from a sales company. I was going to take it and put a pre paid german sim in it. should I pull it out of the box and set things up now or just do it over there. I assume when I buy the sim card a phone company can help set it up

 

thanks

Avoid roaming as it is expensive, just use free wifi, no need to call DTAC as roaming should be automatic, but good to check in advance. But I would not use roaming. Buy a sim in Germany and yes the seller will help set it up.