Hi there, @Scoobyjimbo. I'm here to ensure you'll be able to import your data from QuickBooks Self-employed (QBSE) to QuickBooks Online (QBO).
First, let's download your transactions in a CSV file and upload them into QuickBooks Online. It's up to you if you're going to export everything from QBSE for your records.
Here's how to export transactions that have been added to QuickBooks:
- Go to Transactions.
- You can choose the transactions you need to export by using the Type, Account and Tax Year filters.
- Once you've selected what you need, select the Download icon which is next to the filters. Refer to the screenshot below.

If you want to export miles and taxes, see this article that details the process: Export data out of QuickBooks Self-Employed.
Once done, sign up for QuickBooks Online. Now you're ready to move your data into QBO.
If you plan to connect the same bank and credit card accounts you used in QuickBooks Self-Employed, you don't need to move any transactions. Instead, follow the steps to connect your accounts. If you don't plan to connect the same accounts, upload your CSV file into QuickBooks Online.
When everything is set, let's begin categorising the transactions.
Should you need further assistance in importing data from QBSE to QBO, feel free to leave a reply. I'll be here to lend some help. Take care!