I would like to enter negative amount for an expense, reason being there was discount given. is there any ways that i can force enter a negative amount for an expense?

It's great to have you here, rtek84.

We can enter the negative amount as a Discount item when creating an expense. In QuickBooks Online (QBO), we can use either the Discounts given (Income) or the Discounts given - COS (Cost of sales). In this case, I'd suggest consulting your accountant on what posting account you need to apply in QBO.

Also, we can edit the total price of each item if it is a sales discount since this kind of discount is not booked separately. If it is an early payment discount, create a credit memo using an income account (usually other income) to book the amount. 

Once you have the information you need, here's how you can enter a discount:

1. Open the Expense transaction.
2. Enter the details in the Payee, Payment account, Payment date, and Payment method fields. 
3. Tap the Category drop-down and choose either Discounts given (Income) or Discounts given - COS as advised by your accountant.
4. In the Amount column, enter a negative value of the amount.
5. Enter other details in the Expense transaction. 
6. Once done, press Save and close. 

For more details about creating an expense, refer to Enter, edit, or delete expenses in QuickBooks Online article.

To give you more insights about managing suppliers' transactions, visit our Manage Suppliers and Expenses page.

That should point you out in the right direction today. I'm just one post away if you need a hand with running your financial reports or any QBO related. You have a good one.