If you're looking for the next step up from Xero reminders, look no further. Paycada has a lot more functionality for chasing outstanding amounts, with links embedded it it to speed up payments. Chase automatically until paid, see what's gone out where & everything links both ways with Xero

I love using Paycada, it is a seamless software that does wonders. Has resulted in payment of invoices going back a while that we had long given up on. I would highly recommend.