By Libby Kane

NEW YORK (Learnvest) — Do you know how much your co-workers make? How about your friends?

Money isn’t always the easiest thing to discuss, and when you add workplace dynamics, it only gets trickier.

Assuming your office doesn’t expressly forbid discussing pay, who exactly are you allowed to discuss it with? When is it completely off-limits? And how do these rules translate to discussing salary with friends?

We spoke with etiquette experts, recruiters and HR professionals to figure out when it’s appropriate to talk about your salary — and how to do it.

Why is the subject of salary so touchy?

“So much of who we are is based on what we do professionally, and by extension, what we earn,” explains manners expert Thomas P. Farley (aka “Mister Manners”). ”In American society, much of the respect we get from others is tied to what we earn.”

But this isn’t the norm everywhere. Daniel Post Senning of the Emily Post Institute points out that in much of Europe it’s considered rude to ask people what they do for a living when you first meet them. “If you’re able to engage in pleasant conversation, you’re expected to be able to do it without prying,” he says.

Senning adds that there are tiers of polite conversation, ranging from the most innocuous and widely suitable topics (sports, the weather) to the most intimate topics you should discuss only with close friends (family and finances).

When bringing up a potentially personal topic such as finances you never know where the conversation will lead. “Their favorite topic might be real estate problems in lower Manhattan,” Senning says. “Or they might just have been foreclosed on.”

When you should steer clear of a salary discussion

If your employer forbids discussing compensation as a rule, don’t test their tolerance. “Worst-case scenario, you’ve violated company policy and may be fired,” says Mark R. Gerlach, a career strategist and former recruiter. But more likely, he adds, your co-worker will tell others what you’ve told him and management will think that you can’t be trusted with confidential information. “That’s quite a stigma to carry through your career.”

Compensation also isn’t an appropriate topic for chatting around the proverbial (or actual) water cooler. Robert Duchin, who’s spent his career working as a human resources executive, emphasizes that no good can come of casual salary sharing. “If there is a significant disparity between individuals’ pay, and if the lower-paid person feels like she works harder, has been there longer or holds a more important job, she’ll be demoralized, at the very least,” he says.

Farley brings up a similar point when it comes to discussing salaries among friends. While broaching the topic with a close friend whom you believe is similarly paid might not be the worst thing, talking about salary with someone who makes significantly more or less than you can lead to trouble. He explains that there might be feelings of superiority or inferiority — and things such as choosing a restaurant can become fraught with tension.

Although collective wisdom tends to err on the side of avoiding salary discussions, when we spoke with attendees at LearnVest LIVE, our first-ever live event presented in partnership with Chase Blueprint, we found that 53% of respondents knew how much their co-workers made and 58% knew how much their best friends earned.

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So someone has to be talking about it — in fact, a lot of someones.

When you can open up about how much you make

According to Senning, when you must talk about pay — during a salary negotiation— part of presenting yourself well is doing your research beforehand about what you deserve to be paid. And how are you supposed to do that without talking about salary with other people?

The trick is in who you speak with and how you approach it. Senning and Farley agree a successful salary conversation includes these three elements:

1. A valid reason

We’ve established that talking about compensation outside of an actual negotiation can be problematic, which is why you should consider carefully whether you want to begin that talk. If you’re approaching a negotiation, either with your current employer or a new opportunity, it’s the right time to start doing some research. Farley puts it simply: “If you’re doing this out of sheer curiosity, bite your tongue.”

2. The right person

People whom you may want to approach include close friends in the industry who make similar salaries, a trustworthy colleague who is a level or two above you and might be able to provide perspective or someone who has left the company. If you work for a larger employer, someone in the HR department — the department meant to act as liaison between employer and employee — can give an accurate range of salaries for positions within your company.

3. A respectful approach

Being thoughtful in your approach means flat-out asking someone if he or she is comfortable speaking about the topic before diving in. And begin the conversation in a relatively private place, explain your reasoning for bringing it up and ask for a range, rather than specific figures.

For example, when speaking to someone at a higher level, an appropriate discussion might go something like this: “I’m looking to explore my potential at my job, and I know you’re experienced in the industry. Would you be comfortable sharing with me the range of compensation that someone at my level might expect?”

If, for any reason, the person seems uncomfortable or is unwilling to share, apologize immediately and drop the subject. But if you’ve been thoughtful, respectful and appropriately motivated, the conversation should go well.

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