How do I get the invoice number on the customer's copy of the invoice

It's great to see you here in the Community forum, @levidoesit. I'd be glad to share some steps to help you with your invoice numbers concern in QuickBooks Online (QBO).

If you're referring to adding the invoice number when you send it to your customer, you can customize your form styles so it will show on their copy. Here's how:

1. Go to Settings ⚙ and then select Custom form styles.
2. Select New style or Edit to make changes.
3. Choose the Content tab.
4. Select the header section, and tick the Form numbers checkbox.
5. Click Done to save the template.
   
   

For more details about the customizing process, please visit this article: Customize invoices, estimates, and sales receipts in QuickBooks Online.

If this is not the case, can you please provide additional information about your concern? Any additional information can help us narrow things down.

Additionally, you can check out this article as your reference for receiving and categorizing invoice payments in QBO: Record invoice payments in QuickBooks Online.

You're always welcome to get back to me if you have any other follow-up questions about removing invoice numbers in QBO. I'm always here to lend a helping hand. Have a great day!