Please tell me how to change the banking details on my invoice and quote

Welcome to the Community.

I'll help you change the banking details. However, I need more information.

Invoices and Quotes don't have a bank account added.

If you have added a memo for the bank details of an invoice using a template, you can edit the message and use the template when you create invoices.

Here's how: 

1. Go to the Gear icon ⚙, then click Custom Form styles.
2. Find your custom or standard template.
3. Click Edit in the Action column.
4. Make any edits. Then select Done.

Here is an article you can refer to for the detailed steps: Customise invoices, quotes, and sales receipts in QuickBooks Online.

I'm also adding this article about recording invoice payments: Record invoice payments in QuickBooks Online.

Feel free to click the Reply button below if you have questions about managing invoices. I'm always here to help. Have a great day.