Glad to have you here in the Community, KristiK. 

I'm here to guide you on how you can import transactions in QuickBooks Online.

You can only import your lists (suppliers, customers, inventory, and chart of accounts)  in QuickBooks Online. You can move your existing lists from another QuickBooks Online company. This saves you from having to set up the items from your lists one by one.

Here's how: 

1. Sign in to the account that has your lists.
2. Select Reports.
3. Depending on what list you need to export, search for and run Account List, Customer Contact List, Supplier Contact List, or Product/Service List report.
4. After saving your report, export it.
5. Open the exported report in Excel.
6. Delete rows 1-4 to remove your company name and report title from the sheet.
7. Save your report again as Excel or CSV.

After you export and save your reports, you can import them to QuickBooks Online.

For detailed steps on importing each list, see these articles:

• Chart of Accounts
• Products and Services
• Customer
• Supplier

You can check this article to help you out on how you can export customer information from QuickBooks Online to Excel: Export customer data to Excel. 

Let me know if there's anything else I can help you with exporting customer's data. I'll be right here whenever you need additional information.