Do payment plan Payments for the previous year count as expenses in the current year?

It will depend on your preferences, kevin. 

In QuickBooks Self-Employed (QBSE), we can record the payments on the Transaction tab when we receive payments or paid bills. 

If you made the payment in the previous year, we can record it for that year. Or if it's created for the current year and we account for it for that year.   

However, if you want to post the transaction in the current year, we can delete it and then add it manually with the specific date for the year. 

Here's how: 

1. Go to the Transactions page. 
2. Choose the transaction you want to remove. 
3. Tick the box under the Date column and click the Exclude icon. 
4. Click Apply. 

Then, we can Add transactions to re-create the transactions to change the date. 

Additionally, refer to this article to learn about organizing your data in QBSE: Categorize transactions in QuickBooks Self-Employed. 

Let me know if you have any payment-related concerns in QBSE. Keep safe always!