There are four words people don’t want to hear when they are doing business with somebody: “divorce,” “disability,” “drugs” and “death.” Frederic Marx, a partner at the law firm of Hemenway & Barnes LLP in Boston, calls them the “four D’s.”

When your business partner gets divorced, for instance, it can mean his or her shares are transferred to a spouse who is now a de facto partner in your company, something you might have never foreseen. And a drug problem, whether it’s your client’s or your colleague’s, can greatly harm your business and destroy relationships, yet you still might not want to address the issue head-on because you think of it as a private matter.

Nor do people want to plan for the possibility that the owner of a business might become disabled or die, which in either case would leave a company in disarray.

More financial advisors are preparing succession plans for their businesses and their clients as they age, according to Marx. But almost no one anticipates the “four D’s” in that planning.

“When forming entrepreneurial or family business teams and growing a business, executives and owners must safeguard the company from these issues—whether for the near term or future generations,” Marx writes in a white paper. Advisors structuring businesses for their clients or themselves must be able to anticipate these issues. The key is to prepare for these instances ahead of time with policy, before they become personal.

Before a business partner gets divorced, for example, and his shares are transferred to a spouse as part of a settlement, it’s possible to anticipate the problem by making sure transferred shares are non-voting shares, says Marx.

“That way, when a divorce settlement comes due and shares go to a spouse outside the company, there will be money at stake but not control of the enterprise.” Marx says he draws up an agreement for the spouse (long before a possible divorce) so there are no problems down the road.

Drug abuse is talked about even less frequently.

“I ask clients what they would do the day after they find out a key employee has a substance abuse problem,” Marx says. “The answer cannot be, ‘I don’t know.’ You need a plan.” It’s a particularly sensitive issue for financial advisors since they control other people’s money. That means a person with a drug problem at a planning firm is a potential liability. One way to deal with this is to buy insurance for employee assistance programs.

The partners in a firm will have to have a general discussion and create a policy for everyone before any one person becomes a problem. The question of what happens to a person’s voting rights, for example, in case he is divorced or dies, should be decided ahead of time for everybody. A policy needs to be in place that treats everyone equally and fairly.

“Whether due to an owner’s death, disability, divorce or dependency, stories about corporate disarray emerge routinely around the world,” Marx says. “Giving forethought to such difficult circumstances can provide important clarity that helps companies avoid worst-case scenarios.”