Hi there, Collins. I'd like to provide more information about adding details to the statement in QuickBooks Online (QBO).

Currently, adding payment information directly to the customer statement is not possible. However, you can add payment details directly from the existing invoice under the Memo on statement box.

Here's how:

1. On the left panel. click Customers & leads. Then, select Customers.
2. Find the customer that you want to add the payment details, then select the customer.
3. Once the invoice is found, click Edit under the Action column.
4. Enter the information in the Memo on statement box.
5. Once done, click Save and close.

I've included a screenshot for your visual reference.

Once done, you can generate Transaction Statement to display the information.

Here's how:

1. Go to the +New icon,, then select Statement.
2. Locate the transaction under the Recipient List. 
3. Then, click Print or Preview.

I've added a screenshot for your visual reference.

In addition, you can personalise your sales forms anytime by referring to this article and have detailed steps: Customise invoices, quotes, and sales receipts in QBO.
 

Reply to this post if you still have concerns about your managing your invoices in QBO. I'm here to help.