I'm here to help you un-split transactions in QuickBooks Self-Employed (QBSE), emelie.

To remove the split option for transactions and prevent them from being split in QuickBooks Self-Employed, you can follow the steps below:

1. Navigate to Transactions and locate the transaction you want to un-split. 
2. Click the Split icon.
3. Within the Split transaction window, choose the Trash can icon next to the category you wish to eliminate.
4. Click on Save.

You can check out this article for more detailed steps: Split and Exclude Transactions.

You can also check these articles for future references:

• Manually add transactions in QuickBooks Self-Employed
• Categorize transactions in QuickBooks Self-Employed

Keep your posts coming if you need further assistance un-splitting transactions in QBSE. I'm always here to help. Have a good one.