You’ve been graded for as long as you can remember—you’ll never forget your first gold star. And though you might have graduated, those evaluations don’t end. Instead, the stakes are higher than ever.

In the age of super-hip startups, unlimited vacation time, and jobs that fulfill us, it can be easy to lose sight of why we schlep to work every day in the first place: the money.

Related: Should You Take A Job For The Money?

Yet it’s really intimidating and difficult to discuss your salary at work, either in a formal negotiation setting or with peers. But it’s important to know what’s appropriate when, and how to discuss it without making enemies in the process.

You shouldn’t discuss it at work

It’s against “The Rules”

Just like fight club, the first rule of talking about salaries is never talk about salaries. Says professional career advisor and author of Networking for the Novice, Nervous, or Naive Job Seeker Tom Dezell, “Private companies may have policies regarding this, some may formally write them in policy or handbooks, others simply verbally forbid or discourage discussing salary information.”

These kinds of gag rules aren’t necessarily explicit, because that would be against the law. As a worker in the United States, you’re entitled to talk about pay, according to The Atlantic.

That doesn’t mean that it won’t hurt you at work, though. It’s still completely taboo to bring it up in day-to-day conversation, and could definitely earn you a trip to HR.

It’s too personal

Just like you wouldn’t bring up the election or your religion while at work, it isn’t kosher to talk about your salary. A 2013 Monster.Com poll showed that 63 percent of U.S. workers were uncomfortable talking about their salary at work—ever. Even in the age of the Internet, it’s still a part of basic business etiquette. “[On the list of] things you should never ask someone, how much they earn is one of them,” says Dezell. “It’s more relaxed now, but many still regard it as too personal a question to be asked.”

When you talk about salary, you run the risk of offending someone, or making them uncomfortable. Unless you’re office BFFs, it’s probably not a good idea to mention it—and even then, you should proceed with caution. Says Elise*, a 20-something at a small tech B2B company, “You run the risk of making things awkward, creating an unnecessary competitive atmosphere and potentially causing people think of you in a certain way.”

…Except when you should

“Discussing salary with other employees is stereotypically considered taboo, but especially when you’re beginning a new role, knowing the going salary is fairly important,” says Alaina Leary, a magazine and book editor. “This is particularly true because of the gender wage gap—you don’t want to end up being paid less than your worth.”

Yes, the pay gap is real. By not talking about it, or assuming that you’ll be noticed just by working hard, you can put yourself at a disadvantage.

“I think it’s worth a conversation to compare other people’s experiences,” says Kaitlin*, a millennial based in D.C. “I think a big factor may also be women’s hesitance or fear to ask for what they deserve. We have to practice being strong and demanding without the fear that we’ll be perceived as bitchy or bossy.”

The fact of the matter is: if you don’t ask, you won’t receive. “They’re not going to just roll over and give us what we want if we don’t ask for what we deserve. It’s worth the conversation and you have to fight and make noise about what’s glaringly unfair,” says Kaitlin.

That’s what makes the ‘should you?’ question so difficult. There’s a time and place to talk about your salary: your performance review. “You’ll need a compelling reason,” says Tom. “Often with a boss, it will be a topic in performance reviews, so that can be the way to approach it.”

Related: Everything You Need to Know About Negotiating a Job Offer

This doesn’t mean you only have one shot to discuss your salary. Though your company might have a period of “official” performance reviews, you should be having regular meetings with your manager regarding your personal development—and salary is certainly a topic to discuss.

How to discuss your salary (the right way)

Your boss may be ready to shut you down when you ask—naming budgets, politics, or any other excuse—so if you’re not prepared with information about your performance (and industry benchmarks), you won’t go very far in your negotiation, according to Forbes.

Do your research ahead of time with tools like this free salary calculator or with larger reports from sites like Glassdoor. Understanding where you fit into the grand scheme of your industry, your location, your education, and your experience will help you know if what you’re hearing is baloney or if there’s a real reason behind the “no.”

Industry events can be a great way to chat with women at your level. Talking with peers from different companies in the same industry, if they feel comfortable doing so, can give you a better baseline than online research. Attending a salary negotiation class, talk, or other empowering event like a women’s conference can provide a safe, empowering space to discuss real issues or role-play different scenarios.

If you’ve learned through the grapevine in your company that others in your position are making more than you, it’s critical to stay calm. “Such a realization is upsetting,” says Tom. “But you’ll get better results by approaching the conversation with a tone of ‘It’s come to my attention that others in my role are earning a higher salary than me, what can we work out to increase my compensation?’ as opposed to demanding equal pay.”

The best way to frame your discussion is not on what others are doing, but what you can do. Saying to your boss, “I want more money,” makes you look greedy, desperate, and will immediately put them on the defensive.

Instead, start with how you can do better. “What actions do I need to take that will put me in position for a raise?” or “What kind of performance do you need to see for me to receive a raise next year?” are questions that signal to your boss you’re willing to work for it—and that you want to get better.

Salary is only one piece of the puzzle when it comes to others in your position. There are a lot of reasons why they might be earning more than you. So before you knee-jerk to “That’s not fair!” remember the context. “Some employees have longer tenure, some managers give higher raises than others and some raises are based on different projects or goals that have been reached,” Elise points out.

Talking about your salary is an important but delicate art. Though it’s often considered taboo, there are right times and wrong times to discuss it. Be confident in your abilities, and above all: arm yourself with information. It can make the difference between a raise and a big fat “no.”

*Names have been changed

How to Talk About Salary at Work Without Getting Fired