By Marjorie Adams, president/CEO of Fourlane, a financial technology consulting firm in the United States.

More than one pioneering giant of retail has sworn by the motto, "The customer is always right." While this saying was invented by Harry Gordon Selfridge in 1909 and has been a go-to policy for floor managers and complaining buyers alike, has it always been correct, especially in the business-to-business (B2B) environment?

I say no.

As a policy, it does appear to make solid business sense. Customers pay their invoices to help you keep the lights on and pay your employees, provide referrals to bring in new customers and build your reputation. This is especially true in the always-on age of instant reviews. If you don't have customers, you won't have a business.

But those reasons alone do not mean your customer is always right.

How many times have you heard someone say, "Wait, but the customer is always right. I know how to run my business and know what I need to do." Despite everything we've been taught about the customer, you'll accomplish far more, and improve your bottom line, by standing up for yourself and setting better expectations.

Ensure the customer is heard.

When you get a customer complaint, instead of agreeing with them, the first step is to make sure everyone involved in a supposed problem understands the situation. Whether you're the business owner or a team member, unless you establish transparency with your customers, you'll constantly play the "he said, she said" game, and no one wants that. Instead, customers need to be able to speak their truth with every person involved in a supposed problem. Get it out on the table and discuss it as a team.

Don't take the complaint personally.

Shelve your emotions and calmly hear the customer out, as you might do with a friend who is trying to tell you something you don't necessarily want to hear. And, remember to ask yourself: Is the customer in fact right in this particular instance? Don't immediately challenge the customer -- instead, thank them for their feedback and for the chance to work out the problem.

Retain your focus.

Even if you listen to the complaints of customers, be on guard against letting those complaints take you and your business off course. You don't want to institute a major change based on a customer's complaint that could detract from a thought-out and well-planned long-term project. Some customers create their own complaints by simply expecting you to read their minds, and in a professional services firm, distractions can also cause you to miss deadlines which then causes more complaints from customers.

Think about your staff.

Customers might also feel free to slam a company or specific employee without thinking there would be any kind of consequence. At my company Fourlane, we never allow customers to have offline meetings to complain about one of our staff without having that staffer included in the discussion as well. It's amazing how the customer's attitude can soften when the person they're complaining about is actually present.

The Real Danger

Speaking of staff, let's talk about your employees -- your company's most valuable asset. If the customer is always right, then one of your employees is always wrong. Does that sound right?

Consider the employee who is most involved in the complaint. She needs to know that you'll back her up, unless she's clearly done something wrong, of course. You can hurt your business if that accused employee has to just stand there while you coddle a customer who doesn't have a valid case. That employee will probably feel unvalued, unimportant and like a sitting duck for future customers' opinions and illegitimate gripes.

Why should you care so much about your team when the customer is the one with the money? It's simple. Employees who feel abandoned by management will not do their best for a company. As a result, your customer service will suffer in the long term.

Find Your Sweet Spot

In the face of customer complaints, you may have to do something that can be hard: Understand that not all customers are the right fit for your company.

I occasionally ask our partners why they have not fired a client in a long time. Not everyone can be a good client for us and, if they aren't, we won't be a good consultant for them. 

As we've seen, nobody is right all the time. Spend some time evaluating what makes your best customers the best -- and then you'll see right away the ones that may need to find a new provider. Remember, the customer is not always right.