As per KSA regulations its mandatory to add barcode to the invoice, please advice how can I add this to QBO

You can use a free invoice app to work with ZATCA portal and integrate it with QBO as a workaround.

Hello there! I acknowledge how adding a barcode to your invoice facilitates efficient tracking.

A built-in feature for barcodes isn't supported in QuickBooks Online. However, You'll want to display your barcodes on a specific item by using the Description field of the invoice or adding a custom field.

You can also consider integrating a third-party app to handle barcodes. You can find available apps through this link: https://quickbooks.intuit.com/app/apps/home/en-global/.

Additionally, QuickBooks Online allows you to create scheduled transactions. To learn more about this, please refer to this article: Create recurring transactions in QuickBooks Online.

If you have any further questions, please leave a comment below, and I'll be glad to assist you. Take care!