The Business generates Retainer Invoices to Customers, for pre-payment of Services.

Some of the Retainer Invoices are for 3rd Party Customer Expenses, eg. an Application Fee payment to Government. Thus, it's a Net Zero $ for the Receipt and Expense.

It's not Business Income, as it's just collecting monies on behalf of the 3rd Party and paying it out shortly after.

What's the best way to NOT represent these sort of Retainer Invoices / Receipts as Income?