We can use markup items to apply an additional charge to an order. Using markup items lets us to track markup amounts without affecting inventory valuation.
For example, we can charge a rush fee for completing a service or delivering an item quicker than is usually guaranteed. We can choose to markup the amount for this charge by a flat additional fee. When we add a markup item as a line item, it increases only the line-item amount that precedes the markup item. The markup can be either a percentage of the total amount for the line or flat rate.
The following screen shot example, shows how markup applies only to the preceding line item.

Creating a Markup Item
To create a markup item
Go to Lists > Accounting > Items > New.

- On the New Item page, click Markup.

- On the Markup page, enter an identifier for the item in the Item Name/Number field.
- In the Rate field, enter the rate for this markup as either a percentage or a dollar amount. To indicate a percentage, type a % sign after the number. To enter a dollar amount, enter a positive number.

- On the Accounting subtab, select an Account.
- Click Save.