When creating a new document you can change the date. For already issued invoices it’s still possible to change the date and the number, but this operation is to be done very carefully, as it may create inconsistencies in your accounting systems.
When creating a document (invoice or quotation) it must be compulsorily selected from among those existing in a customer master data in the section customers. When modifying an existing document you can edit customer data directly from this screen.
You can add product lines to your invoice. Product lines are 2 types: descriptive and priced.
Prized lines perform automatic calculations and update the total, description lines instead only add lines of text. With the add-on “services” enabled you can directly search for the product/service into the search box and the line will be automatically completed.