The waiting time for receiving an unlock code for Acer phones starts from 24 minutes to 48 hours.

Unlocking instruction for Acer Iconia Smart ?

How to enter an unlock code in an Acer Iconia Smart:
1. Turn on Acer Iconia Smart with an unaccepted sim card inserted (from a different network)
2. enter the unlock code provided by sim-unlock.net

Your Acer Iconia Smart is now unlocked.