[Blacklac]

When I hit voicemail, I don't get asked to set one up. I'm not sure how to.

I came from a Blackberry on ATT, btw. So I had voicemail setup previously. I am using a new SIM now, if that matters at all.

[ninjaap]

Try dialing your own number with area code. If that doesn't work, call 611. Maybe, ATT needs to flip a switch to turn your voicemail on.

[palandri]

Try pressing and hold down the 1 key.

[Blacklac]

Try pressing and hold down the 1 key.

that gives me the same message as the voicemail button. "If you have a box associated with this account, please enter the #". Or something like that.

[Blacklac]

Dialing my own number gives me a busy signal.

[ninjaap]

Call 611. Going from one platform to another (like BB to WP) will cause ATT to reset your plan. Voicemail is a feature and needs to be added your account.

[kevm14]

My voicemail number in the phone was set to 203 area code (southwestern CT), which I thought was strange, because I am in RI. I changed it to my own number, though it seemed to work fine with the 203 area code number.

[EricCantona]

I don't know if you've resolved this yet, but you need to call ATT customer service and tell them you want to set up a voice mail.

This happened to me when I switched from iPhone to Wp7 (same carrier). But it doesn't happen to my friends. I guess it's random?

[boneycat]

I had the same issue. I had to call ATT since the person who programmed the new sim card forgot to re-activate my VM since I had the unlimited data plan. At least that's what the CS told me.