Valentine’s Day is a great day on which to terminate a long-term relationship that has irretrievably gone sour. I just fired a client, and, as usual, I am left with pangs of guilt mixed with a bittersweet sense of liberation.

It happens to all of us on occasion – a customer (external or internal) becomes financially or emotionally unbearable, no transformation is possible, and we are faced with the prospect of enduring the pain or terminating the relationship. It is always difficult. The hardest part is making the decision to let go, though the older I get, the easier it is for my growing cynicism to win out over my fading romanticism.

Once the decision is made, it is easy to break the news if the customer is someone you really dislike. But it is so much harder if you have bonded personally. Somehow “it is business, not personal” doesn’t cut it.

There is usually some kind of fall-out when you tell a client that you no longer wish to do business with them. Sometimes there are hurt feelings, indignation, legal repercussions, or threats that “you will never do business in this town again.” I have found the best way to minimize the fall-out is to communicate unemotionally and professionally the reasons why, after repeated efforts at redefining the relationship, you can no longer engage with them.

If the reasons are personal (you just can’t stand the person), it’s better to provide an easier rationale for them to swallow, no matter how much anger you are bottling up inside. It makes for a swift, clean break, rather than starting a new battle. I have tried giving people plenty of notice, and sometimes your contract or your integrity dictates it, but it is rarely appreciated. You have to keep asking yourself if the client would summarily pull the plug on you were the shoe on the other foot, and then act accordingly. Loyalty to a customer should not be earned easily.

In retrospect, I should never have got into bed with many of the clients that I have eventually “let go”. There is a time in the evolution of a business where any customer is seen to be a good customer. Particularly in the early days, big household-name companies exploit your eagerness to have them on your client list, and they negotiate deals which can be absurdly one-sided.

Common come-ons are the promises of instant credibility, of doors to dozens of other companies flying open, of unspecified “bigger things” waiting around the corner once you sign this one loss-leading agreement. The reality is that once you have agreed terms that are punitive, it is incredibly difficult to claw your way back into a more balanced relationship.

On occasion I have had more faith in a client’s products than they have, and have invested accordingly. In the start-up days of an e-learning development business when big-name training organisations approached me to help get their courses online, I sometimes abandoned my principle of never doing anything that doesn’t have a clear path to profit.

In my eagerness to encourage them to make the leap, I took on projects at a loss, with my upside tied up in a share of future revenue. A couple of those deals paid off well enough to cover the money pits that the others became, but the losers should have been ditched a lot earlier than they were. The client I just fired, after five years, was one of those.

In the past three decades, of the dozen or so customers whose agreements I have prematurely terminated, most have been large corporations. Typically, they have become over-demanding to the point where the cost of doing business has outweighed the benefit of having them on the books. But there are others where the reasons for walking away have had something to do with my own integrity. I have not liked their business practices or their people, or have fundamentally disagreed with what they have wanted me to do. I fired one Fortune 100 company because they took four months to pay their invoices; another because the senior executives I had to deal with were obnoxious; and another because they insisted I implement a training solution when clearly the problem was organisational.

What if you don’t have enough clients to be able to walk away from one of them? You can get trapped into believing the gambler’s lie that by staying in the game you might eventually come out on top. But the longer you stick with the loser, the less likely it is that you’ll ever build a big enough client base to escape.

Life is too short to be spent indulging the egos of others at the expense of your own, or subsidising the businesses of companies who could lose your annual revenues in a rounding error. But once you are in such an abusive relationship, it’s a challenge to get out. Valentine’s Day is one artificial horizon that I use every year to assess where I am with my various clients. And if the romance has gone, it may be time to be moving on.

* Read more of Godfrey Parkin's columns here.