How can I record Supplier settlement discount?

Joining you here to offer my help with your question about discounts, muzi.industrial.

You can record a supplier credit for the settlement discount. Then, apply it to the bill to lower down the amount of the payment. I'd be glad to share all the steps with you.  

First, create a vendor credit for the discount. Here's how:

1. Click the + New button and select Vendor credit or Receive vendor credit.
2. In the Vendor dropdown, select your vendor.
3. Depending on how you record purchases with this vendor, enter the Category details or Item details. Usually, this is the category, product, or service you’re getting a credit for.
4. Select Save and close.

Second, follow these steps on how to apply the credit or discount when paying the supplier bill:

1. Go back to the + New button and select Pay bills or Pay bill.
2. Select a bill for your supplier from the list. You'll see the available credit with this supplier in the Credit Applied field.
3. Enter all other details and choose Save and close. 

Details about this process are shared in this article for additional details: Handle Supplier Credits and Refunds in QuickBooks Online.

Don't hesitate to reply to me and let me know if that lets you record the settlement discount. We're always here to help if you need anything else.