The generally accepted turnaround time for invoice payment on professional services is 30 days. Some clients take a little longer, very (very) few pay more quickly, and the majority are right on the money at 30 days.
Not me; I’m a super-fast payer. Not for people like the phone company or gas company, but to another professional — particularly if it’s a solo person — I pay the minute I get the invoice.
Why? Because it’s a nice gesture that costs me close to nothing and yet is always noticed on the other end. The way I look at it, being viewed by the professionals I depend on as a fantastic client is worth more in a pinch than having the money sitting in my bank account for another 30 days.
Try it. Next time you call for a favor, I’ll bet they go out of their way to help you too.