Is there a way to duplicate transaction? I want to duplicate a transaction for to remind me for next years taxes

Good to see you here, MrEngineer13. 

I'll share different information on how the transaction works in QuickBooks Self Employed.

The option to copy the transactions to remind you for the next year taxes isn't available in QuickBooks Self  Employed. As a workaround, you can enter the transactions manually. 

Here's how:

1. Go to the Transaction menu at the left panel
2. Select Add Transaction.
3. Enter the amount and a description.
4. Choose the Select a category menu. Then, select the best category to organize your transaction.
5. If you have a receipt, you can drag and drop it onto the form.
6. Once done, click Save.

For additional information, you can click this article: Manually add transactions in QuickBooks Self-Employed.

Just in case you want to learn how to categorize your transactions correctly, you can read this article here for detailed information.

Please post a reply below if you have other concerns with your transactions in QuickBooks Self-Employed. I'll be more than happy to assist you again. Have a great day and take care always.