The simple negotiation tactic this career coach used to secure a $20,000 raise at her last job

Career coach and entrepreneur Ariel Lopez.
Photo credit: Ariel Lopez

Negotiating your salary can be difficult. And in many cases, employees leave thousands of dollars on the table when they aren't equipped with the right tools and knowledge to ask for more.

That's why, in addition to giving the common advice about researching your market value in order to know your worth, career coach and entrepreneur Ariel Lopez says she always advises her clients to give a range for how much they want to make rather than an exact number. Following this tactic, she says, typically helps a client "land a way higher [salary] than what they originally wanted," which leads to less money left on the table.

"I think that [tip] changes lives totally, my life included," she tells CNBC Make It, while explaining that this tip can be helpful to anyone looking to get a pay raise at their current job or negotiate a salary at a new job.

Prior to stepping out on her own in 2016, Lopez, who is now the founder and CEO of the hiring platform Knac, says she was able to negotiate a $20,000 raise at her last job by using the salary range method that she advises her clients to use.

Career coach and entrepreneur Ariel Lopez.
Photo credit: Ariel Lopez

"I actually used that tactic twice," she says, while adding that within a two-year time period she had two separate salary negotiations that led to her receiving a total pay increase of $40,000. "So it definitely works when you use the range [method] and stick to it."

When giving a range, Lopez says she always tells clients to ask for 10-20% more than what their base salary currently is. For example, if someone is making $70,000 then a 10-20% range will be $77,000-$87,000, or she says you can just round it up to $80,000-$90,000. Doing this, she says, allows you to have more wiggle room on the amount an employer might offer.

"Usually what happens is the company will come back and they'll say, 'Okay, I can do $85,000,'" she says. "And now you have a $15,000 increase on your salary as opposed to only having a $5,000 or $7,000 pay increase because you gave an exact number."

While salary negotiations can be nerve-wracking, Lopez says that one of the biggest mistakes she's seen employees make is not asking for the money they deserve because they think someone else will recognize their work.

"Rarely does someone stop by your desk or send you an email and say, 'Hey, we love your work so much we're going to give you a raise, right?' Like that doesn't really happen," she says. "No one is going to advocate for you the way you advocate for yourself so just ask for the money. The worst they can say is 'no.' And the best thing that they can say is' yes.'"

Check out: 5 tips for successfully switching careers in the new year, according to career experts

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