Customer notes

You can add a new custom field to your transactions in QuickBooks Desktop, Andy. This note will be displayed on every invoice and sales order once it's added to your template. Let me show you the steps below.

Before adding a custom field to your sales forms, you must first enter the information for the specific customer.

Here's how:

1. Go to the Customer center.
2. Locate the customer you want to add a note.
3. Double-click it and click Additional Info.
4. On the Custom Fields section, click Define Fields.
5. Add the word Notes to the list, then click OK.
6. Once done, click OK.

After adding, you can modify the format and include a Note field in the template used for each customer transaction.

Here's how:

1. Go to Lists and select Templates.
2. Choose a template. Then, double-click it.
3. Select Additional Customization to add the custom field.
4. In the Header section, locate the Notes you have added.
5. Then, mark it check under the Screen field. 
6. Once done, click OK.

If you need guidance, refer to this article to learn how to add custom fields in QBDT.

Furthermore, you can convert your sales order to an invoice without making a new one to your customer. Refer to this article for guidance.

It's been a pleasure interacting with you today, Andy. If you have further concerns about managing your customers. Don't hesitate to reply. We're one post away to help you. Take care.