I put the wrong year of bank opening balance should have been 06/04/2020 not 06/04/2019?

It's nice to see you in the Community, @aspirationds.

You can edit the opening balance through the register. Here's how:

1. Click the Gear icon at the top. 
2. Pick Chart of Accounts. 
3. Locate the account, then go to the Action column and select View register.
4. Find the opening balance entry.Tip: If you've got the Date column sorted from newest to oldest, the opening balance entry is likely at the bottom or end of the list.
5. Choose the opening balance entry once you've located it.
6. Edit the Date. 
7. Hit Save once done, then Yes to confirm. 

You can take a look on this article for more information: Edit an incorrect opening balance.

If there's anything else you need help with, let me know by adding a comment. I'm always here for you. Have a good one!

**Say "Thanks" by clicking the thumb icon in a post.
**Mark the post that answers your question by clicking on "Accept as solution".