We print and mail invoices. How can I update the STATUS within INVOICES to show that they have been sent?

Hi there, @kovanda.

QuickBooks Online (QBO) only tracks transaction sent inside the program. You'll want to send the invoices to your customer within QBO to show the invoice status Sent.

In your QBO:

1. Go to the Sales menu.
2. Select the Invoices tab.
3. Locate the invoices you want to have the sent status.
4. Select Sent from the Action drop-down menu. 
5. Enter the email address of your customer and click Send. 
6. Once done, the invoices will have the Sent status. 

I've also got you this great article that can guide you in customizing your invoices in QBO: How to Customize Invoices in QuickBooks Online.

You can always count on us if you need further help with invoicing in your QBO account. We're always here ready to help. Happy holidays!

Please read my question again.

We MAIL the invoices, as in print and send via USPS with a stamp.  We do not send via email.

Is there a way to document that an invoice has been MAILED so we know it has been completed??

THANKS

Glad to see you again, @kovanda,

QuickBooks will only track transmission status when the invoice is sent through email inside the program. While USPS is a third-party source, any mails or submissions there will not be recorded in our system automatically.

The best way to handle this is tracking the mail manually in the USPS website and recording it in QuickBooks. You may add a customized field for the mail status then assign it to the sales transactions. Here's how: 

1. Click on the Gear icon and select Accounts and Settings.
2. From the Sales menu, tap on Sales form content section.
3. Under Custom fields, enter a description in the Name field.
4. Mark the Internal and Public boxes. See sample screenshot below:
   
5. Click Save and Done.

You can also do this in the Custom Form Styles window. Here's how:

1. From the same Gear icon, choose Custom Form Styles.
2. Find the invoice template then press Edit.
3. On the Content tab, pick the template header.
4. Hit the + Custom field link.
5. On the empty field, check the box then enter the custom field description.
6. Click Done.

This option will create an additional field on the invoices for you to fill out manually.

Check out this article for future reference: How to add custom fields to invoices?

If you have any questions related to QuickBooks, please drop them here and mention me anytime. I'll be right here to help you succeed. Have a nice day!