Although most clients will tend to pay with a credit card, we know that there are others that still prefer to pay with good old cash currency. Not to worry!
If you receive a cash payment and need to provide change you can simply add a negative payment to the invoice.
Say the client owes $85 on an invoice and they pay with a $100 bill. Your invoice will show a -$15 balance.
You can then apply a -$15 payment with a note stating that it was change, and the invoice will balance to $0.
Note that we also have plans to make this easier with our payments updates coming soon.