Dealing with difficult clients is sometimes necessary, but there are two types of customers that simply aren’t worth negotiating with: The customer who turns irritable, and the one who sees things only in black and white. This article explains how to spot these two types of customers early on in your negotiation.

Dealing with difficult clients can be an absolute pain. These kinds of customers make what should be an easy sales deal a long, drawn-out, complex process. Inevitably, you’ll come across customers who just waste your time, such as the flip-floppers, ho-hummers and don’t-know-what-they-want clients (or the person who wants it all, without paying for it). But, the worst kind of customer is one who’s not worth dealing with at all.

Two types of customers simply aren’t worth negotiating with: The customer who starts off courteous and then turns angry, and the customer who sees things only in black and white. Here’s how to spot them early on in your negotiation:

The customer who starts off nice, then turns irritable

If you think about a typical negotiation or sales process: the recipient starts off leery of your product or service. Then, you have to work to convince the other party of their need, and (hopefully) she'll buy in. Once the customer sees a demonstration or plan of how you will deliver, she begins to build trust in what you’re saying. If you were to chart her interest on a graph, it would be a steady increase over time.

However, the reverse situation—someone who starts out excited, but grows increasingly defensive—should be a red flag. This kind of behavior suggests that the customer wants control rather than a compromise or solution. Another warning sign is when the customer who grows defensive seems to buy back in, just after you start to walk away from the deal. If you were to chart her “interest” on a graph over time, it would be a jagged, up-and-down zig-zag. Because this type of person wants total control over the situation versus a final purchase, this sale is not worth pursuing.

The customer who sees things only in black and white

Another basic ingredient of successful negotiation is the ability for both parties to reach a compromise. That may mean simply the final exchange of money for a product or service, or it may mean that you include an additional item your client wants in order to come to a final sale. If you’re working with a customer who has set ideas on what’s “right” and “wrong,” you may have difficulty in persuading him to come to a compromise in negotiation. This type of customer puts everyone into “good” and “evil” buckets, and it’s hard for you to change that designated standing with him after the fact. You’ll never be able to come to an agreeable conclusion, because this customer doesn’t believe you are worthy of their funds.

As much as you want to make that sale, there’s a point where you’ll need to cut your losses. Dealing with difficult clients is sometimes necessary, but these two types of customers won’t be worth your time or energy.