Hi @JMAC67,
Thank you for posting here in the Community. I can help you fix the bank error when uploading CSV files in QuickBooks Online.
You usually encounter an error if you don't meet the requirements for uploading bank transactions manually. Please note that the maximum file size is 350 KB.
If the file exceeds the limit, shorten the date range and download transactions in smaller batches. To know more about how you can check the format, check out this link: Format CSV files in Excel to get bank transactions into QuickBooks.
For more information, as well as how to fix different banking errors in QuickBooks, I recommend the following article: Format CSV files in Excel to get bank transactions into QuickBooks.
Feel free to hit that Reply button if you need more help with QuickBooks Banking or fixing bank errors. Have a great day ahead.
