You've come to the right place, @lbrock. I'm here to help with preparing 1099's.

Just to clarify, are you needing to add expense accounts for 1099 tracking? If so, this can be done with just a few clicks in QuickBooks Online. Here's how:

1. Select Expenses on the left navigation panel and choose Vendors.
2. Click Prepare 1099's.
3. Navigate to Section 2: Accounts within the 1099 Wizard.
4. Place a check-mark, if there isn't one already, next to the box that you're categorizing payments for. 
5. Select the Choose an account drop-down and place a check-mark in the boxes next to the accounts that you'd like to add. 

The following is a brief video to serve as a reference:

After you've added the accounts for 1099 categorization, continue through the wizard. I'm also including an article that covers solutions to common issues when preparing the form: 1099 Troubleshooting.

All done. I'm sure you'll have the 1099's ready in no time. 

Should you need anything or have questions, I'm just a few clicks away. Have a good day.