Can I automate the uploading of invoices along with their corresponding Excel attachments in QuickBooks, or should I handle this process manually instead?

Hi there, Linet.

Currently, QuickBooks does not support uploading invoices with their associated attachments. However, let me share some workarounds to help you achieve this. 

You can consider importing your invoices and manually attaching their corresponding Excel file to QuickBooks Online to achieve this process effectively. To do so, please follow the steps I'll share below.

Before you proceed, please take note that you can import a maximum of 100 invoices at a time, with each spreadsheet limited to 1,000 rows. You have the option to include single or multiple line items and import information related to customers, suppliers, or products and services. However, please be advised that discounts, credit notes, and negative amounts are not allowed.

With that, let's proceed in uploading your invoice to our software. To do so, please follow the steps I'll share below: 

1. Prepare and ensure your spreadsheet is accurate.
2. Activate custom transaction numbers.
3. Once done, upload your spreadsheet to QBO.
4. Align your import fields.
5. After ensuring everything is correct, you can go ahead and import your invoices.

For more detailed information regarding the steps above, please check out this article: Import multiple invoices at once in QuickBooks Online.

For effective management of your customers' unpaid and overdue payment balances in QBO, please check this article: Run an accounts receivable aging report.

You can always use the comment section if you have questions about importing sales forms in QBO. I'm here to assist you whenever you need.