When every dollar counts—as it especially does in these tough economic times—many couples decide to go into business together.

But just because you live together doesn’t mean that you know what it would be like to work together. Personality traits that might be acceptable at home—forgetfulness or procrastination, for example—can set off alarms in the office. Common traps and what to do…

TRAP: Having differing levels of risk tolerance. Problems arise when one spouse is comfortable with taking greater financial risks or making bigger monetary investments in the business than the other. To determine the risk comfort zone for each of you, start by defining the lines beyond which neither of you will go.

Example: Are you both willing to use your home as collateral for “seed money” or to finance inventory purchases with credit card debt?

If you are the more risk averse partner, have your spouse show you the numbers. You may find that there is a greater margin of safety than you realized or, conversely, that you both need to do a little more research before taking the gamble.

TRAP: Failing to establish boundaries between work and home. Some couples find that business is all they talk about, which can put a strain on the relationship. Establish ground rules.

Example: Best-selling authors Paul and Layne Cutright (who co-own The Center for Enlightened Partnership) have established a “no business discussion” rule for their bedroom. Other couples agree not to talk business during dinner or after 9 pm.

TRAP: Not operating as a team. It’s important to present a unified front to vendors, clients and employees. While you both need to agree on who handles what areas of responsibility, you still must function as a unit.

This can be especially challenging when one partner has difficulty making or supporting decisions that are likely to upset a third party, such as refusing to extend credit to a customer or disciplining an employee. Successful entrepreneurial couples check with each other before making any important commitments, back each other up in public and work through disagreements in private.

TRAP: Not having a written agreement. In my eight years as a business coach, I’ve heard the same faulty reasoning repeatedly from couples (“We don’t need written agreements—after all, we’re married”) and watched months down the road as the venture and the marriage unravel because of it. Couples need a detailed partnership agreement identifying the goals for the business as well as the responsibilities of each partner.