I am emailing an invoice to my customer need some help?

I've come to help you correct the bank details on your customised invoices when emailing them to your customers in QuickBooks Online (QBO), @siskin1977. With this, you can keep your business's info on your sales forms accurate.

The bank details you see on your customised invoice and while viewing the form's preview should be the same even when you email it to your customers. You may have made some updates or used other templates while emailing the invoice to your customer that's why the bank details show incorrectly. 

With this, I'd recommend resending or re-emailing the invoice using the appropriate template. To do this, here's how:

1. Go to the Sales menu.
2. Select the Invoices tab.
3. Find the invoice and select the View/Edit option under the Action column.
4. On the Invoice page, click the Customise option and select the appropriate template.
5. Click the Save and send button.
6. Fill out all the necessary details (i.e., Subject) and select Send and close.

I've attached screenshots below for your reference.

After that, your customer should now be receiving the correct bank details from the invoice you've resent.

Additionally, you're able to create your invoice template and import them to QBO. This way, you can reflect your brand identity into your sales forms with less effort and time. You can learn more about this by checking out this article: Import custom form styles for invoices.

Let me know how it goes in the comments below. If you have other invoice concerns or inquiries about managing your sales transactions in QBO, I'm just around to help. Take care always.