Yes, you can can invoice your customer for partial completion of a project. Here’s How:
In the Item Details section, click the More icon (…) next to the line item you have added.
Select Add Additional Information.
You can also bulk associate projects to multiple line items. To bulk update:
Click the Bulk Update Line Items option above the Item Details table on the right.
Click Update Projects.
Select the projects to update from the Projects dropdown.
and GST filing.