Hello, jmikewhittington.
Thank you for reaching out to the Community. In QuickBooks Online, merging two companies isn't possible. Each company in QuickBooks Online is treated as a separate entity with its own set of financial data and settings.
However, other ways to consolidate financial information include exporting data from both companies and importing it into third-party software. You can visit QuickBooks Online App Store and search the app name on the search bar that integrates with QuickBooks.
It'll always be my pleasure to help if you've got questions other than moving another company to a different QBO company. Just leave them in the comments below, and I'll gladly assist you. Have a great day!