In the list of Sales invoices there is a column for MEMO. but on the actual invoices there is no MEMO box.

Let me share some insights about invoice memo and how it works in QuickBooks Online (QBO), uvcolourtb.

The option to show the Memo column when creating an invoice is unavailable in QBO. Also, when creating an invoice, there should be three fields (boxes), like the Message on the invoice, the Message on statement, and the Attachments on the bottom left of the screen. As a workaround, we can add a custom field on an invoice and name it a Memo. The option to customise fields is only available in QBO Essentials, Plus, and Advanced. I'll show you first how to turn it on under the Account and Settings page:

1. Click on the Gear icon. Then, select Account and Settings.
2. Select the Sales tab and go to Sales form content.
3. Under Custom fields, turn on the fields you want to customize.

Then, we can go to the customer's profile and visit the Transaction List tab to check what information from your invoice will show under the Memo field in QBO. The Memo field or column in the Transaction List tab on your customer's profile will only display messages indicated in the Message on statement box. In case your notes are written in the Message on the invoice box, you'll have to open the form to review them.

I'd suggest submitting a product suggestion directly to our software engineers. We're taking notes of your ideas and insights. Here's how:

1. Go to the Gear icon at the top.
2. Click Feedback.
3. Enter your comments or product suggestions.
4. Then tap Next to submit feedback.

Your relevant feedback goes to our Product Development team to help heighten your experience using the program. Also, you may want to check out one of our Help pages as your reference to guide you in managing your company's income and customers in QBO: Sales and customers help for QuickBooks Online. 

Let me know if you have other concerns about managing and customising your invoices. I'm always ready to help. Take care, and I wish you continued success.