How do you fix ,every time a input a Bank transfer from one account to another ,a duplication occurs ,so my account bank balances on quickbooks are way o

Hi there, maags. I have the right information you needed to avoid duplicate transactions in QuickBooks Online.

It's more likely that you didn't match the bank transfer you entered in QuickBooks to the downloaded transaction from your connected bank.

I'll show you how to link them together so you can prevent duplicate entries.

To match:

1. Go to the Banking/Transactions tab and hit Banking.
2. In the For review tab, click the transaction (bank transfer) to expand and view the details.
3. Tick the Find match radio button. 
4. In the Match transactions page, filter the transactions by choosing Transfers from the Show drop-down, and set the From and To dates.
5. Select the bank transfer you recorded, then Save.

For more information about managing bank transactions, you can check out this article: Manage your bank transactions in QuickBooks.

I've also added this link as a future reference once you're ready to reconcile an account in QuickBooks Online.

Feel free to return to this thread if you have follow-up questions or other concerns about banking. Take care!