How do you change the name on an account register after it is set up but before it is used?

Nice to have you in the Community space, @ruth-cawood.

I'd be glad to walk you through the steps in changing the name of your account register. With just a few steps, and you're all good to go. Here's how.

1. Sign in to your QuickBooks Online (QBO) account and navigate to the Accounting menu.
2. Select Chart of Accounts.
3. Locate the account you want to edit, then click the drop-down arrow under the ACTION column beside the View register link and select Edit.
4. Change the name of your account under the Name field, then click Save and Close. 

You can also read through this article to learn some tips in managing your accounts: Learn about the chart of accounts in QuickBooks.

Let me also add this link that you utilize for future reference: Reconcile an account in QuickBooks Online. This provides detailed steps in matching your bank and QuickBooks balance seamlessly.

In case you have other questions managing your chart of accounts, you can always tag me in your reply. I'll be around to help you. Keep safe!