Getting paid quickly is often influenced by the payment options you offer. You'll be paid more quickly if it is convenient for your client or vendor. Some ways to speed up payments include:
Avoiding Net 15 or Net 30 option if you can
Offering ways that your customer can pay at the time of service (online or via smartphone)
Considering adding a way that they can pay directly from the emailed invoice
Consider offering an ACH payment option for quicker payments with lower fees
Enforce automatic, recurring payments if possible
Implement a process for ensuring invoices are correct
Consider offering a discount for early payments