Partial payment question
I sent an invoice to my client and they have paid 50% for booking of my service. The partial payment works well with displaying of the paid amount and balance to be paid which is another 50%.
Upon job completion, i want to charge my client another 50% for the last payment. I try to send the same original invoice which has now shown the amount paid and balance, however i can't change the invoice date. The latest invoice should be able to cater for the new date as I will be sending another updated invoice which shown the amount remaining to be paid but I can't be using the old date of the initial invoice sent out because it is not fair (send the first invoice on 26 Nov 2018) and my terms of payment is 30 days. If I can't change the invoice date, what is the solution?