Requesting payment on a past due invoice requires an approach that balances assertiveness and professionalism. Keep detailed records to make the process easier, and track invoices by number and service date. Define your payment terms on each invoice, so you can reference your company policy when making collection and follow-up inquiries.

Friendly Phone Call

Make a phone call to request payment on a late invoice. This can be especially effective if you have a familiar relationship with the customer and assume the late payment was an oversight. For example, “Hi Stan, this is Jane Smith with ABC Company. I want to make sure you got the invoice we sent you for last month’s shipment. It was dated January 15, 2015. It’s 10 days past due, so I’m wondering if it got misplaced? I can send you a copy right now if you like.”

Formal Phone Call

If you’re trying to get an invoice paid through a large company’s accounting department or by an unfamiliar individual customer, a more formal tone is appropriate. Identify yourself, be specific about the nature of the call and make your request. “This is Jane Smith with ABC Company. I’m calling with regard to Invoice #1234 submitted to you via mail on January 15, 2015. The invoice is currently unpaid and I’m calling today to ask what kind of payment arrangements you’d like to make.”

Written Request

Much like formal and informal phone calls, the way you make a written request for payment depends on the nature of your business relationship. An informal email to a regular customer can be simple, such as, “Just checking in on your outstanding invoice from last month. I’m attaching another copy in case you need it.” It can also be formal and assertive, noting the nature of the delinquency and the consequences for continued non-payment. “If this account remains unpaid for longer than 30 days from the invoice date, you will be subject to a 10 percent late fee and future collection efforts.”

Make Payment Easy

When making your payment request, give the custom several options to speed the transaction. For example, offer to accept payment via a credit card over the phone, cash or money order via mail, or electronic payment through an online banking or e-pay site. Ask for immediate payment to avoid further delays. If the customer can’t pay, ask for a partial payment or an agreement to pay at a predetermined future date. Put all agreements in writing.

Take Legal Action

Your request for payment may carry more weight if you have an attorney draft it. This may be a consideration when the outstanding invoice amount is significant or is more than 90 days late. You can also consider small claims court or employing a collection agency to assist with your efforts. Don’t let unpaid accounts linger for months at a time. The longer an invoice goes unpaid, the greater the likelihood you won’t see payment at all.