Hi there, @Eady2021.

Thank you for reaching out to us here in the Community. I can provide clarification about updating the opening balance details in QuickBooks Online.

Yes, it's safe to change the date and amount of the Opening Balance Equity. The details should be accurate to reconcile the account correctly and avoid discrepancies.

Also, I recommend seeking expert advice from an accountant regarding excluding transactions from the prior month. This way, you'll be able to ensure that the process is adequate and your books are error-free.

Check out this screenshot for your visual guide:

For additional reference, you can use the following link to learn more about how to organize your accounts, like assigning account numbers in QuickBooks: Learn about the chart of accounts in QuickBooks.

Leave a comment below if you have other concerns regarding the chart of accounts or opening balance. The Community and I will be around to help you.