Hello there, @Mragu18. Let's get you through this so you can import invoices inside QuickBooks Online (QBO).
Reading your post, the option to input a custom transaction number may be active in your QBO. That said, you'll want to ensure that the option to enter a custom invoice or transaction number is disabled inside your company file. This way, QBO can take control of the numbering sequence and follow the next transaction number for your imported invoices. We'll be happy to write down the steps to get you going:
- Access your QuickBooks Online company.
- On the top-right corner, click the Gear icon and then select Account and settings.
- Select Sales.
- In Sales form content, select Edit ✎.
- Turn Custom transaction numbers off.
- Select Save, then select Done.
For more details, please see this article: Add custom transaction numbers to sales forms in QuickBooks Online.
Once done, try importing your invoices again. Feel free to refer to this page for more details: Import multiple invoices at once in QuickBooks Online.
In addition, we go these articles to help you manage invoice payments, and keep track of transactions entered inside QBO:
Please don't hesitate to inform us here in the Community space if you need further assistance importing invoices or have any additional QuickBooks-related concerns. We'll be around to help you out again. Stay safe, and have a good one.
