When I create a new invoice and save, the status changes to paid with a zero balance

I can help you figure out why the status is paid with a zero balance when creating a new invoice, acecleaningspeci.

Your customer may have existing available credits, and the Automatically apply credits feature is enabled. Once this option is turned on, it will automatically apply to the next open invoice.

You'll want to check from your Settings if this is the case. Once verified, you can turn it off.

1. Go to the Gear icon and choose Account and settings.
2. Select the Advanced tab.
3. From the Automation section, toggle the Automatically apply credits.
4. Click Save, then Done.
   

Turning off the feature will no longer apply credit notes to open invoices moving forward.

Open the invoice, then click the Payment hyperlink at the top right to verify what payment is applied. 

Once you verify it's the auto-apply credit note, you may consider deleting the payment or unlinking it if you don't want it to auto-apply to your customer's invoice.

For additional information, check our create and apply credit notes or delayed credits in QBO.

I'll be right here to keep helping if you have other questions about managing customers' invoices in QBO.