I have opened an account of supplier with opening balance, Opening balance is being shown as expense
I can tell why the opening balance of the supplier is categorised under an expense account, rajeevbehal1.
The expense account is selected as the default account when the QuickBooks Online subscription is created. It appears in the Debit column on the transaction journal and can be edited once the original transaction is created.
Income and Accounts Payable (A/P) or Trade and other Payable accounts are impacted when you enter an opening balance of a supplier. And, AP will be impacted by this entry until the bill is paid.
To edit the expense account that the opening balance is assigned to:
Go to Expenses, then Suppliers.
Select the supplier, then select the Opening Balance Bill.
Change the expense account in the detailed line item of the bill and choose the account you've opened for the supplier.