I need to go back and add more receipt details to the receipts I've already matched. Will I lose all the info like "names" I added if I hit "undo" to add in more info?

Hey there, usermontytrucking.

Thanks for dropping by the Community, I'm happy to help. What you're going to want to do is edit the receipt rather than hit the undo button. Hitting the undo button will likely delete all the information such as transaction names. However when you edit it, you'll be good to go, to do so, follow these steps:

1. Click Customers
2. Then Create Credit Memos/Refunds. 
3. Save & Close.

You can find additional information on these steps provided in this helpful article about editing a sales receipt. 

If there's anything else I can do for you, feel free to post here anytime. Thanks for stopping by and have a lovely day.