How do you add an address tag to an invoice so that the customer can connect it to the right job? Do I just put it under the message section?

Hi there, 

Welcome to the Community. Tags are customizable labels that let you track your money however you want so you can get deeper insights into your business. Rest assured, I'll be happy to share more info so you can continue to create your invoices with confidence. 

In order to user tags, it's vital to make sure you've enabled the feature through your settings. Once the feature is enabled, you'll see a Tags fields when creating an invoice. You can use this field to enter your tags so you can keep track of the invoice with ease. Here's a helpful video tutorial that explains more about enabling the feature and tagging your everyday transactions in QuickBooks: What are tags and why should I use them?

Let me know if this info helps. I'll be one message away in case you need anything else.