To create an invoice in Odoo, you need to fill in the following mandatory fields
Customer Information
Customer: When selected, Odoo automatically populates information from the customer record including invoice address, receivable account, and other details. You can edit these values directly on the invoice if needed for this specific transaction.
Invoice Details
Invoice Date: If not set manually, this field is automatically populated with the current date when the invoice is confirmed.
Due Date: Specifies when the customer must pay the invoice.
Journal: Automatically set but can be changed if necessary.
Currency: If the invoice currency differs from the company currency, the exchange rate is automatically displayed.
Invoice Lines
In the Invoice Lines tab, you need to add:
Product: Click "Add a line" to search for and select the product.
Quantity: Specify how many units.
Price: Enter the unit price.
Taxes (if applicable): Select appropriate tax rates.
Additional Information
You can also include optional information in the "Other Info" tab such as:
Customer Reference
Payment Reference
Other custom fields
Note that Odoo initially creates invoices in Draft status. They have no accounting impact until they are confirmed, at which point Odoo assigns each invoice a unique number from a defined sequence.
If you need to make additional fields mandatory (such as Fiscal Position or Customer Payment Terms), you can customize the form using Odoo Studio or by modifying the view's XML code.