I am migrating from QB Desktop 2013, which has been a great system that lets me amend transactions when the need arises. Does QB Online have this same functionality?

Hi there, @qboa-basics4busi.

Yes, you're right. You can modify your entries in QuickBooks Online anytime you want. 

 To learn more about the differences between our two programs, check out this link that shows the comparison between QBO and QBDT software.

Additionally, I encourage you to visit our Get Started with QuickBooks Online guide for reference. From there, you can read some of the additional resources we offer to help you going.

Reach out to me again if you have follow-up questions or concerns about the QuickBooks migration. I'll be around for you. Take care and have a great day ahead.

@Doug_B4B 

If you are a veteran QB Desktop user, I would recommend sticking with QB Desktop. If you are using QB Desktop UK version, you can purchase the one time license of QB Desktop 2020 UK version to upgrade your file. If you are using QB Desktop US version, you can purchase the one time license of QB Desktop 2021 or QB Desktop 2022 Accountant edition. You can setup a simple private cloud if required to work similarly to QB Online.