discount on an invoice line item

Welcome to the Community, @Derek_D.

You can consider using a discount line item to apply a discount to one or more items on the invoice. To do that, you'll need to create a discount item first before applying it on the invoice. Let me guide you how.

1. Click the Gear icon.
2. Select Products and Services.
3. At the top right, select New.
4. Choose Service for Products/Services type, then complete the information needed.

• In the Name field, enter Discount. If you plan to create multiple discount percentages, you can enter the percentage and Discount for the name (Example: 10% Discount).
• In the Sales price/rate field, enter the discount amount as a negative. (You can manually calculate the discount amount based on the percentage promo)
• From the Income account drop-down, select Discounts given account.
• In the Sales tax category section, it depends on your state if sales tax is calculated after discounts are applied then mark the discount line taxable.

      5. Click Save and close.

Once done, you can now use the Discount item on an invoice. Here's how:

1. Click the Plus (+) icon.
2. Select Invoice.
3. Choose the appropriate customer.
4. Add the product and services, then enter the total amount of the item.
5. Select the Discount item on the next line.
6. Click Save and close.

In case you need tips and related articles in the future, visit our QuickBooks Community help website for reference: QBO Self-help. 
 
Feel free to visit us again if you have any other questions with QuickBooks. We're always here to help.

Hi, Derek_D

Create a service type Item called Discount and connect Income account - Discounts ( expense type ) and Expense account - Uncheckamrk OR Discounts received ( income type ) for bill/expenses screen.

For, Discount item select the out of scope tax rate and enter the discount amount as the negative amounts

Now you can select the Discounts as you need for each line items 

to display the total discount amount customize the invoice 

Note do not checkmark Total discount on the invoice customization instant create your own custom field and enter the total discount amount.

Check the attached sample invoice 

Note: 

Should taxes be applied before a discount or after?

in the above solution Selling price is subjected to Sales taxes therefore
speak to your tax consultant if you want to exclude sale taxes on selling prices
and use net price after discount
If taxes are excluded selling price is
Sales price (-) Trade Discount = Net Selling Price
No Discount item on the invoice.

Trade discount transactions are not included in QuickBooks.

* OR

use tax codes/rates for Trade discount check the attached sample invoices comments below

transactions are entered in QuickBooks and on the invoice as well.

Comment back for further clarifications / to discuss.