Use These Strategies to Get Paid More Quickly You don't have to always be at someone else's mercy.

First step: Set better terms. Otherwise, you're at someone else's mercy.

At one of my companies, we sold six-figure packages of services to Fortune 500 companies. We assumed that getting a signature on a purchase order meant we'd be paid. That turned out not to be true, because our customers' accounts payable departments often had very different ideas. So once we wised up, we made sure someone in their accounts payable signed off on our payment terms before we provided the services -- and we made sure to find out exactly who would be handling our invoice and payment.

Related: Freelancer's Guide to Getting Paid Online

Speaking of invoices: The more thorough they are, the faster you get paid. They need to describe everything ordered and/or services provided. They need purchase order numbers. (A copy of the actual document doesn't hurt.) You want to provide them with absolutely everything you can to prevent them from delaying payment because, as we've probably all heard before, they "don't have enough information." Also be sure to provide clear and complete payment instructions, including prominent display of the date by which they've agreed to pay.

If your client is late on payments, don't include a line at the bottom of invoices or statements that shows how far behind they are. It may feel satisfying, but I've found that it has an unintended consequence: It gives payers the unspoken permission to pay the oldest amount due, rather than the entire amount due.

For substantial invoices, consider contacting your customer's accounts payable department 10 days before the payment's due date. Say you want to make sure they have everything they need. Tone is everything here: Don't demand a prompt on-time payment. Instead, ask if you can help them. I call this "training the customer to pay."

Related: 9 Ways Freelancers Can Get Paid on Time and Avoid Deadbeat Clients

So now that you've done everything you can to get paid, you can speed up the process even more by how you accept payment. Here's a rough breakdown.