Hi there, melanie-errico.
Though we're unable to merge the two accounts, the best option I can suggest is to export the lists. Then, we can import it to the other QuickBooks Online account. However, you don't have to do this if these two accounts have exactly the same data.
- Go to Reports.
- Run Account List, Customer Contact List, Vendor Contact List, or Product/Service List report depending on what list you need to export.
- Customize the list report’s columns.
- Click on the Export icon and choose Export to Excel.
Please check these links for more details:
For the bank transactions, you can either manually upload transactions or connect bank accounts to QuickBooks Online. In addition, you can follow these steps on how to update your billing details. Make sure you have Master or Company Admin rights.
- Go to the Gear icon and select Account and Settings.
- Select Billing Subscription and click Edit beside your payment method.
- Update your credit card info. Click Confirm card or Save.
Post again here if you need more help. Wishing you all the best!