Upvote:1
As others have mentioned, check if your phone is a GSM phone.
Another option is to just buy a cheap pre-paid phone in Belgium when you're there. You can sometimes buy these phones for €20.
Upvote:3
You might have a problem operating the AT&T Go-phone in Europe, depends on the phone model. Usually they sell older simpler dual-band phones as Go-Phones, and these phones won't work on European GSM frequencies. You need a 3-band or 4-band phone (sometimes described as "world phone" or "international phone"). Check with AT&T (or online by the model number) if your phone is of that kind.
If it is, and is unlocked, then any Belgium GSM provider should work. They have pre-paid SIM's there as well, but can't tell you which one and for how much as I used my own iPhone with the AT&T SIM (paying tons of money) when I was in Belgium.