6 salary negotiation mistakes that could be costing you

There's a paradox in corporate America, and workers are losing out.

Entry-level workers often get the impression they have to take whatever salary they are offered, while employers are typically sitting at the table primed for negotiation.

"Most employers expect that they will offer a low number and a candidate will counter with what they feel they should be paid," said David Fletcher, director of career development at American University's School of International Service.

But a majority of American workers fail to do this. Nearly six in 10 workers did not negotiate and instead took what was offered to them, a recent Glassdoor survey found. For women, the problem is even worse. A full 68 percent of the women Glassdoor surveyed accepted the first offer presented to them.

While candidates might be hesitant to haggle, the reality is they have greater leverage than they'll probably ever have again because employers want to reel them in. The only remaining question is "At what price?"

While the difference between an initial offer and a negotiated package might add up to just a few thousand dollars per year initially, there's much more at stake in the long run.

"If you are starting your career and you undervalue yourself by a few thousand, over the course of your career that can be tens to hundreds of thousands a year," Fletcher said.

Here are six mistakes to avoid to boost your chance of coming out of negotiations on top:

While your prospective employer doesn't want to lose you and will most likely be willing to work with your counteroffer, it's crucial to counter with a package that is realistic for your position and industry.

A good rule of thumb is coming back with a number that is at most 10 percent higher than what is offered, Fletcher said.

Hammering out a package each side will be happy with is a give-and-take process. Don't dig in your heels and refuse to meet somewhere in the middle.

While email is great for sending messages to colleagues, emailing headhunters or human resources to negotiate often ends poorly.

Emails can easily be misconstrued. Also, candidates' negotiating resolve might melt away if the prospective employer takes his or her time in replying to a counteroffer.

Bottom line: This is a business decision. It's not a reflection on you, but rather how much an employer is willing to pay you to do a specific job. It's the employer's goal to get the best candidate without breaking the bank.

Come to the table with a back-up plan. If your counter offer was dead on arrival, try bringing up another perk that you would be happy with instead, such as an extra week of vacation, continuing education benefits or perhaps transit money.

Getting your way after considerable back-and-forth communication isn't really winning if it comes at the expense of your relationship with your future co-workers. At the end of the day, you do have to work with them if you choose to accept.

"You may end up getting your way but if you've really worn out HR and were a bear to deal with, you may come across in (a) poor light," Fletcher said.

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