You can run a report in Salesforce to verify that the accounts in each entity are synchronized correctly.

1. In the Reports tab, click New Report....
2. Expand the Accounts & Contacts folder, and click Accounts with Billing Accounts.
3. Click Create.
4. In the Billing Account: Info folder, drag Entity ID and drop it in the Preview area.
5. Click Run Report.
6. Verify that the Billing Accounts belong to the correct Entity IDs.