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

Unlocking instruction for Acer Chromebook Tab 10 ?

How to enter an unlock code in an Acer Chromebook Tab 10:
1. Turn on Acer Chromebook Tab 10 with an unaccepted sim card inserted (from a different network)
2. enter the unlock code provided by sim-unlock.net

Your Acer Chromebook Tab 10 is now unlocked.