By default, your services will be tracked against the default account code you specify when setting up your Xero or Quickbooks integrations, however you can override this for individual services.
Attributing Services to Different Sales Account Codes
You can assign specific sales codes in your Xero or Quickbooks account to individual line items.
Step 1. Head to Configure > Line Items
Step 2. Edit the relevant service.
Step 3. From the integrations tab, assign the account code
From the integrations tab, you will be able to specify an account code to send this service to, for both Quickbooks and Xero.
The drop down will pull up a list of all of your current Xero or Quickbooks account codes for you to choose from.
Step 4. Save your settings!
You're good to go.