In Odoo 17, you can efficiently import customer invoices and vendor bills using the built-in data import feature. Here's a step-by-step guide to help you through the process:​

1. Prepare Your Import File:

• Export a Template:
  • Navigate to the Accounting module.
  • For customer invoices:
    • Go to Customers > Invoices.
  • For vendor bills:
    • Go to Vendors > Bills.
  • Select an existing record, click on Action, and choose Export.
  • In the export dialog, select the necessary fields you wish to include.
  • Export the file in either .csv or .xlsx format. This file will serve as your template.
• Populate the Template:
  • Open the exported file in a spreadsheet editor.
  • Add or modify records as needed, ensuring that all mandatory fields are filled correctly.
  • Save the updated file.

2. Import the Data into Odoo:

• Return to the Accounting module.​
• Navigate to the section corresponding to your import:​
  • Customers > Invoices for customer invoices.
  • Vendors > Bills for vendor bills.
• Click on the Import Records option.
• Upload your prepared .csv or .xlsx file.
• Map the columns from your file to the corresponding Odoo fields.​
• Click Test to validate the data.
• If the validation is successful, click Import to finalize the process.​

3. Post-Import Actions:

• After importing, the invoices or bills will be in the Draft stage.​
• Review each record to ensure accuracy.​
• Confirm the invoices or bills to post them.​