Use the Transactions app to convert your transaction files to required by your accounting software file format.
This tutorial shows how to import a QBO file into Quickbooks Online.
Login into Quickbooks Online to import a QBO file and click on 'Banking'.
If you have the account already created, select that account. Look for the 'File Upload' button and click on it.
Look for the 'Browse' button.
Click on it to browse for the QBO file. Then click 'Open' and 'Next'.
Review that QBO file you are going to import: filename, Account ID, Account Type, and Date range.
If everything looks good and this is the correct QBO file, select the Quickbooks account you want to import your data into. Then click 'Next'.
Then click 'Let's go!'.
Click 'For Review'. You can see four transactions are imported. The Description is actually the Payee name from the QBO file. The Payee column is empty because this is Vendor records in Quickbooks to match. Now you have to categorize the transactions and match them to Vendors or Payees. Click on the transaction.
And then select Vendor records and Category, which is expense or income account.
Click 'Add' to add the transaction to the register. Continue for all transactions.
Let's say you realized, that it is an incorrect imported QBO file or something wrong with a file, and you don't want those transactions to be here. So, select all transactions.
Then select 'Batch actions' and click 'Exclude Selected'.
Go to 'Excluded'.
Select all of them again and then select 'Batch actions' and click 'Delete'.
So, this way, you completely delete those transactions from Quickbooks Online.