If you would like to void an invoice in Enrolmy, follow the steps below:
Navigate to the Money Tab → All Invoices
Open the invoice you want to void
Click on +More symbol, and then
Select Void Invoice
Follow the prompt and provide a reason for voiding the invoice
Navigate to your Money tab again, select the '+' tab → Void, u will see the invoice appear in the list of voided invoices.
Opening up the void invoice will show you the reason why it has been voided