upgraded iPhone 4 to 4S.. tell AT&T to update IMEI?

[unlimitedx]

I used another line in my family plan for my upgrade to the 4S. I just plugged in my sim card from the iphone 4 to the iphone 4s. Do I need to call at&t and tell them to update the IMEI in their system? (not auto detected by at&t?)

 

[sb1805]

It couldn't hurt. I just did the same thing. There's talk that updating the IMEI allows you to select the new 4S data plans, which supposedly are required for the new HSPA+ speeds.