When creating invoices or sales receipts, you can input the code under the Description column. Let me walk you through how.
Open your QuickBooks Online account, then select Invoice from the (+) New icon.
Fill in the required details, then select the item/s under the Product/Service column.
Add the code under the Description column.
Save the transaction.
I understand the importance of adding a custom field to your products/services. Rest assured that our engineers are working non stop to enhance the product for our customer's convenience. You may check out our blog to check for the latest QuickBooks updates and feature enhancements.