It is possible to create partial/split invoices. There are two ways to achieve this:
1. Set up Invoice moments.
In this step you determine in how many parts the invoice is going to be split, and which part should be invoiced when. This can be done by setting up invoice moments. When generating your invoice, the percentages determined in your invoice moments will show.
2. Split invoice when generating.
When generating an invoice, 100% of the project's total is automatically selected. If you want to create a partial invoice, you can uncheck one of the checkboxes in the 'Project sum' section and insert a percentage.
When you will create the invoice for the rest of the project, you can subtract the amount already invoiced in the 'Invoices to subtract' section.
3. Partial payment.
If you have the Quoting & Invoicing add-on. You can now, after generating an invoice, click on the status to add a partial or full payment to the invoice.