I have been searching through the documentation, and it looks like this can't be done, but I thought I'd ask just in case.
I have an office cleaning business. Invoices are sent out monthly. Some months have more cleaning dates than others, so the total service charge fluctuates even though the per-cleaning charge does not. I also sell products. The sales total fluctuates as well, depending on the amount of supplies used. Customers do not order products themselves, but leave that up to me.
My customers want to enter their credit card one time and let me charge that card automatically each month. Is there a way to facilitate this with Zen Cart? I am using Paypal Web Payments Standard.






