Why is there multiple invoices created for One Customer

When you have multiple invoices for the same customer

 

If a student does multiple classes or there are siblings in a family the system will generate one invoice with all the details on it. There is one reason why there might be 2 invoices created for the same customer outlined below:

Why
The reason is that you have added a student to a class then have generated an invoice for them. After this, you have added the student to a new class and then generated more invoices. In this case, you will have two invoices for the same customer.

How to resolve
To resolve, you can delete both invoices that have been generated for this customer and then click 'Generate' again and it will just generate the one invoice for them.
For this, go to 'Customers' > 'View All' and choose the customer who has multiple invoices.

Once on the customer's page, go on the tab 'Billing' and open the invoice(s) you have to delete. 

Finally, just press the button 'Delete' in 'Invoice Options':

Alternatively, you can head to your invoice list, 'Billing'> 'Invoices', search for the customer's name in the search bar, select both of their invoices and under 'Group Actions' use the 'Delete' function.
After this, you can simply click 'Generate Invoices' and after selecting the relevant season it will create one invoice for that customer.