How do I enter a payment as a split payment on one transaction?

Thank you for choosing QuickBooks, @thediyvillage.

I'm happy to share some information about handling split transactions in QuickBooks Self-Employed (QBSE).

We can split transactions or payments downloaded from the bank.  However, income transactions can't be split to both income and expenses, and vice versa. 

For your detailed reference, check out these steps:

 Here's how: 

1. Click on Transactions at the left pane, then select Split from the Type column. 
2. Split the transaction by Amount or Percentage. You can also add a line and choose multiple categories from one transaction.
3. Click Save when done. 

You can also add a rule to the Split transaction. Simply check the box at the bottom that says: Always split (transactions). 

To learn more about this topic, check out this article: Split and Exclude Transactions. 

On the other hand, if you wish to enter a partial payment on your invoices, there isn't a way to do this in the invoices section. The feature is at the moment available in our QuickBooks Online small business packages only.

Also, you can read through this article to learn more about what you can do in QBSE: QuickBooks Self-Employed Overview. 

Please know that I'm always here to help if you have any other questions. Mention me in the comment section below. Keep safe!