How many invoice can be send through invoice

Hi there, AROWSKI. 

Thank you for reaching out to the Community. In QuickBooks, we don't have any limits in sending invoices. You can send an invoice to multiple email addresses by doing either of the following: 

• Typing in multiple email addresses separated by a comma and space.
• Using the Cc (carbon copy) or Bcc (blind carbon copy) fields.

To send your invoice to multiple email recipients, follow these instructions: 

1. From the invoice window, type in the email addresses separated by a comma and space. Take note that there is a 100-character limit in the email address field.  
2. Enter the email addresses in either the Cc or Bcc field.
3. Tap Send.

You can also enter the default email addresses. It helps you avoid entering the same email addresses each time you create a sales form: 

1. Go to the Gear icon and select Account and Settings.
2. Pick the Sales tab, then go to Messages.
3. Click Edit , then enter the default email addresses in the Cc or Bcc field.
4. Press Save.

You can read through this article for more detailed steps about adding emails on sales forms: Email a sales form or report to multiple email addresses.

Additionally, you can also send invoices from your Gmail address. This way, you can manage your emails with customers all in one place. 

On the other hand, If you wish to send multiple/bulk invoices at once, you'll be able to do it in QuickBooks Online. Just one click with all your invoices. 

1. Go to Sales, then choose Invoices. 
2. Make check all the Invoices, under Batch actions, chose Send. 
3. Provide your customers email address. 
4. Click Send, once done. 

 That's it! Let me know if there's anything else I can help you with. Have a great day!