It'd be my pleasure to help, @mkennedy2000.

In QuickBooks Online, you can customize what your customers can see on their invoice. You can uncheck the option to display the markup so it won't show when printing the transaction.

Here's how:

1. Open the invoice transaction with the markup percentage.
2. Click the Gear Icon on the upper-right side of the transaction as shown in the screenshot below.
3. Customize the transaction by clicking the Customize what your customers see link.
4. Select the Content tab and click the middle part of the displayed transaction.
5. Click the Show more activity options link.
6. Uncheck the Show markup on billable expenses option.
7. Click Done when finished.

This will no longer show the markup on your client's billing. 

For other related articles you can use in the future, you can visit our help site for information: Income and expenses for QuickBooks Online.

Please feel free to let me know if you should need further assistance with your markup or any other QuickBooks topic. I'm always here to help. Hope you have a wonderful week.