PHP Authentication with monthly billing

Question

A startup client of mine is looking to launch a SaaS with multiple features/options that would increase/decrease monthly billing.

The simplest solution would be best.

Answer 1

If you're looking for a third-party system to hook into, Spreedly looks pretty promising.

Answer 2

I would check on each login when was the last time the user paid, if it's more than a month ago, you make the user go to a payment page (paypal, a cgi from your client's bank...) and have him pay the amount you calculated from the options he uses this last month.

Maybe a simpler solution is to have the user paying "at the beginning" instead : each month he choose what options/features he will use during the next month and then pay for that.