Hello there, @ShoaibAnjum. I'll be glad to help you with uploading your bank transactions flawlessly.
If you've manually downloaded the transactions from the bank, you'll need to review these transactions and make sure it's CSV file format. CSV files are formatted differently by each bank.
Moreover, please review the column, format, and header mapping of the CSV file in QBO. You can upload CSVs in either the following 3-column or 4-column format. Also, know that the maximum file size is 350 KB to successfully upload those transactions in QBO. To learn more about how to check the correct format in importing your CSV file, you can refer to this article: Format CSV files in Excel to get bank transactions into QuickBooks.
You can also check out this article for a more detailed guide in manually uploading transactions into QuickBooks: Manually upload transactions into QuickBooks Online.
Once you've successfully uploaded your bank transactions in QuickBooks Online, you can now match and categorize those transactions. After that, you might want to read this link that serves as your guide in reconciling your accounts effectively: Reconcile an account in QuickBooks Online.
Feel free to post a reply if you have any other concerns with managing your bank transactions in QuickBooks Online. I'll be glad to assist you. Have a good one!
