quickbooks desktop pro 21

In 20 back up the data file

in 21 restore the backed up data file

From what you're describing, this will mean copying recent transactions entered into your older QB 2020 file file by accident into your QB 2021 company file.

QuickBooks doesn't have the built in ability to copy transactions from one company file to another. However, you can do it with our BRC Transaction Copier , which will pull transactions from one company file and help you import them into another file.

Hey there, @lucer. 

Thanks for reaching out to the Community for support. 

When upgrading QuickBooks Desktop, you go through a process of upgrading the company file to the same release as QuickBooks. Once the company file has been updated and opened in the newest release, it can not be opened again in an older release. The only way you could open the company file in an older release would be to restore a backup before the update took place. 

That said, I wanted to let you know that you can't take certain date ranges of data and transfer it into a new release. However, you can upgrade the entire file to 21 again. I've included some steps to open your company file in 2021 below. 

1. Make sure all users log out of your company file.
2. Open your new version of QuickBooks Desktop.
3. Select Open or Restore Company if you don't have a company file open.
4. Click on Open a company file, then Next. 
5. Sign in to your company file as an admin user.
6. Before you upgrade, QuickBooks automatically creates a backup of your existing company file. You can choose Change this default location to save the backup in a specific folder.
7. Hit Update Now to start the upgrade.
8. When QuickBooks finishes, tap Done.

You can see additional details in Upgrade your company files after you switch to a newer version of QuickBooks Desktop. 

Please don't hesitate to let me know if you have any questions or concerns. I'm always around to lend a hand. Take care!