They call you in a panic. They need your advice right away. You drop everything and work hard to get them the information, documents or whatever they need. Then they sit on your invoice for months.

Hopefully, this scenario represents only a small portion of your clients. But for many firms, it represents far too many.

Past-due accounts are a nuisance at the very least. At worst, they represent spoilage – time and effort expended for compensation you’ll never receive.

So what can you do to minimize past dues? Several ideas come to mind.

1. Be clear about your payment policy.

Do you have due dates for invoices? What should clients do if they have questions or concerns about a bill? What happens when an invoice is past due? Do you charge interest?

All of these questions need to be answered up front in an engagement letter. Review the engagement letter with your clients to avoid surprises.

2. Perform credit checks on new clients.

If you’re going to extend credit, you have a right to know whether the client is creditworthy.

Have the client sign the appropriate forms to allow you to pull a credit report. Then, extend credit on the basis of those findings. If the client has been a poor credit risk to others, there’s no reason to think he won’t be a risk to you.

3. Get a portion of your fee up front.

It is not unusual to ask for a retainer, especially for new clients.

Make it clear if the “pay as we go” format will continue past the initial retainer amount. If so, be sure you’re keeping up with your time and expenses so that you’ll know when to send the next retainer invoice.

4. Specify due dates on invoices.

“Net 10 days” is not a good due date. Assign a specific date, such as March 15, so that no ambiguity exists about when the bill should be paid. A specific date also simplifies entry into any client’s accounting system that pulls invoices by the due date.

5. Clarify the procedure a client should follow when questioning a bill.

Specify in your engagement letter the time period for reporting billing disputes or questions. A period of 10 to 15 days is generally adequate. By stipulating a period for raising questions, you show the client that you are fair, but you also minimize the chance that the client will use “disputed charges” as a reason for late payment. A client who doesn’t dispute the bill initially has less of a case for crying “foul” later.

6. Take action if the invoice is not paid on time.

The old adage, “The squeaky wheel gets the grease,” is very true, especially when it comes to collections.

A reminder call is entirely appropriate when a bill is past due. On the first call, nicely let the clients know that you noticed their bill had not been paid and wanted to be sure they had received the invoice.

If they haven’t received it, e-mail or fax a copy right away. If they have, ask when it is scheduled for payment.

Repeat the clients’ promise to them, such as, “Great, then we’ll expect to receive the payment by the 23rd.” Often, that’s all it takes.

They know you’re keeping up, so they are more likely to mail the check. If they don’t, move on to more serious steps.

7. Accept credit cards for payment.

Like it or not, we live in a world where credit cards are more popular than cash or checks.

They’re convenient, they spread bills out for your clients, and they help clients keep track of where their money is going. For all those reasons, you should accept them.

There are a number of merchant programs on the market that allow you to accept the most popular cards for a small monthly fee and sometimes a percentage of the sale. You’ll easily recoup that amount in the time and energy you’ll save by having fewer past-due invoices to follow up on.

As a service provider, you sell an intangible product. As time passes, it is very easy for clients to lose sight of the value you provided to them.

The longer you wait to collect your fees, the more likely the client will be to stall or to find reasons not to pay at all. You’ve done the work; you deserve to be paid. The key is consistency and follow-up.