I upgraded to QB Simple start from self employed. My previous invoice in self employed did not show up on the balance sheet in simple start. Why is that?

Hello there, @ thebodyphasebyco.

Usually, before you can change your plan, you can move your QuickBooks Self-Employed data to QuickBooks Online. You can follow the steps below.

1. Go to the Gear icon and choose Billing info.
2. If you see the Explore QuickBooks Online plans, select it to start the upgrade.
3. If you don't see this option, don't worry. It means you'll need to manually move your data. We'll show you how to do that in the next section.

I'll add this article you can read about upgrading to QuickBooks Online for a reference: Switch from QuickBooks Self-Employed to QuickBooks Online.

Also, it’s possible that the transaction from your QuickBooks Self-Employed hasn’t exported. Let me show you how to do it.

1. Click on Transactions on the left navigation tab.
2. You can choose the transactions you need to export by using the Type, Account, and Tax Year filters.
3. Once you've selected what you need, click on the Download icon located to the right of the filters.

Once done, you can manually import the file to your QuickBooks Online account. For your reference, you may check out this article for further guidance: Export then import list data into QuickBooks Online.

If you have any other issues or concerns by leaving a comment below. I'm always here to help.