The instructions below show you how to setup the My Accounting Toolbox system to skip over predefined accounts using the User Defined Field in Autotask.
Create a User Defined Field in Autotask called XeroNoSync
Description: User to define how they want to describe
Sort Order: 1
Field Type: List
Don't Sync : true
Allow Sync: false
Default Value: Either allow sync or don't allow the sync to be your default
You can use any descriptions you prefer, however the stored values must be either true or false
From the CRM feature - Open the Account of the customer you wish to automatically skip in the sync process, then select Edit.
Under User Defined look for the field XeroNoSync that you created earlier set the value you match your requirements.