Is there a way to have a special wording on invoices but only for specific customers?

I can help you in customizing your template, @anna54.

Can you tell us more about the special wording or the fields that you're referring to? That'll surely help us provide an accurate solution to this question. 

You can create a template and use or set it as default when you create an invoice to a specific customers. Before you proceed, you'll have to enable this feature:

1. Go to your Gear icon and click on QuickBooks Labs.
2. On the page that appears, toggle to On the option for Import Styles. 

Once you're done, open a Word document and start creating your format. Take note of the field codes of your file. These are the keywords that can ease the process of mapping QBO data to dynamic parts of the template. 

For detailed instructions and to check for a sample file, see this article: Import custom form styles for invoices or estimates. Also, here's more information on how to customize invoices, estimates, and sales receipts in QuickBooks Online.

Let me know if there is anything I can help you with or you mean something else, by leaving a comment below.​ Enjoy the rest of the week!