The next button will be unclickable on the final step if QuickBooks detects an error in your CSV data, Long.

Let's ensure that the column mapping aligns with QuickBooks fields and that the file meets these requirements to avoid issues during the import process:
 

• Each line item needs its own invoice number, customer, invoice date, due date, item amount, and item tax code.
• Each imported spreadsheet can contain up to 1,000 rows.
• You can import a maximum of 100 invoices at a time.
• You can't add negative charges, such as discounts or adjustment notes.

Here's a comprehensive guide to help you successfully import multiple invoices at once into QuickBooks Online.

You can also check this article for additional information about uploading files to QuickBooks: Common questions about importing data to QuickBooks Online.

Recording customer payments in QuickBooks is also essential for keeping track of your sales. Check this article for your guide: Record invoice payments in QuickBooks Online.

Feel free to share any additional details below if you need further support with the importing process. We're here to assist you.