AT2Sage allows you to setup Nominal Codes for different Billing Codes, for example you may want Bench Work to use Nominal Code 4001 and Onsite Support to use Nominal Code 4002. This allows you to create more detailed reports in Sage Accounts.
Although you can also create these Nominal Codes in Autotask, the current Autotask API does not allow AT2Sage to download these Nominal Codes. Therefore if you want AT2Sage to use Nominal Codes they must be setup in AT2Sage.
The Default Nominal Code is used for the Nominal Code of items that do not have a Nominal Code setup in the list above. If there is no Default Nominal Code AT2Sage will use the Default Nominal Code from Sage Accounts for that customer.
For more information on Autotask Billing Codes visit https://ww4.autotask.net/help/Content/AdminSetup/1FeaturesSettings/FinanceAccountingInvoicing/BillingCodes/BillingCodes.htm?Highlight=billing%20codes