It pays to ask.

Most new hires simply accept their job offers without negotiating for more – and that’s costing them thousands of dollars in potential salary and benefits, according to a new CareerBuilder survey.

More than half (56%) of workers confessed they don’t negotiate for better pay when they are offered a job, either because: They’re uncomfortable asking for more money (51%); they’re afraid they’ll lose the position (47%); or they don’t want to seem greedy (36%).

This backs previous research by job site Glassdoor, which found three in five employees accepted their first salary offer – particularly women; 68% of them didn’t negotiate, compared to 52% of men – a whopping 16-percentage point difference.

Get over it. Most employers expect candidates to respond with a counteroffer, which is why 52% of bosses told CareerBuilder that they lowball the starting salary so that there is room to negotiate. And more than a quarter of them said the initial offer is $5,000 less than they’re ready and willing to pay.

Watch this: Need a raise? This FBI negotiator shows you how

Michael Erwin, senior career advisor at CareerBuilder, told Moneyish that many workers are still suffering job insecurity in the wake of the 2008 recession – even though skilled workers are in demand right now.

“A lot of people became unemployed, and when they did find a job, they were quick to just accept anything that was offered to them because they needed money coming in, and I think people are still feeling some post-traumatic stress here,” he said. “We have to change that way of thinking. It’s always OK to go back with a counteroffer.”

That’s something that Jennifer Beeston, a vice president of mortgage lending, learned the hard way while she was rising in her career.

“I got hired by a manager whom I had worked with previously, and I believed him when he said his offer was the best he could offer me,” she said. That included paying a $200 fee on every loan she originated, and him taking 10% of her income.

“I found out five years later that he had screwed me royally with those caveats, which ended up costing me $50,000 that first year, because I didn’t negotiate – I just trusted a former colleague,” she said. “You’ve got to know your worth, and find out what everyone else is quoting before you accept.”

See also: 10 jobs where workers are vastly underpaid — and probably don’t even know it

Laura Handrick, 56, an HR analyst at FitSmallBusiness.com, never accepts the first pass. She told Moneyish that she was able to get an extra week of vacation, and Fridays off to volunteer locally, while working at one business a few years ago. She also landed an extra $21,000 on a contract several years ago.

“The first offer is not the final offer. It’s the offer they hope you’ll take,” she said. Plus, asking for more, “proves you can negotiate, which most business leaders – and most men, frankly – appreciate.”

Stop leaving money on the table. Erwin and MaryJo Fitzgerald, Corporate Affairs Manager at Glassdoor, told Moneyish their tips to getting what you’re worth.

  • Do your homework. We all need to do a better job of understanding our market worth, and the best way to do that is to do your research,” said Fitzgerald, including Glassdoor’s “Know Your Worth” salary calculator, which takes your experience, your location and your occupation into consideration. “There’s so many tools out there like this now, that you’re doing yourself a disservice if you don’t do your research,” she said. This will also ensure you’ll make a reasonable offer.
  • Work out what you’re going to say. Most people are uneasy talking about money. Frame your request like, “Thank you so much for the offer. I’m really excited to work here. The salary range I was expecting is something more like this. Is this offer negotiable?” And take it from there. Olivia Jaras, 33, a salary coach, also scored life-changing perks such as coming in 30 minutes late every morning to take her daughter to daycare, and being allowed to work out during lunch. And she simply said, “I’m thrilled with the offer, and I can’t wait to get started. That said, I have a couple of items that I need to run by you before I sign off.”
  • Practice. “Similar to what you do with job interviews, you need to rehearse saying what you’re going to ask for out loud so that you get comfortable with it,” said Fitzgerald. Practice in front of a mirror or with a friend. And while some negotiations do occur over email, Erwin says it’s better to call with your counteroffer, if you can’t get a face-to-face meeting. “The sad thing about technology is that a lot of what we’re trying to say gets lost in translation,” he said. “Just going back and forth over email with ‘I need this much money’ may look like you’re greedy or unhappy, where on a personal phone call, the employer can hear the excitement in your voice about working at the company, and be more likely to say, ‘You know what? Let’s see what we can do.’”
  • Haggle for more than money. When there is a salary cap, and you can’t get exactly what you want, being compensated with flexible hours, extra vacation days or other perks can help bridge that pay gap. “Maybe there’s a transit benefit to help cover your commute, or childcare credits, or perhaps they serve meals in the office or free coffee, which can save you a lot of money,” suggested Erwin.
  • Keeping asking. Negotiations don’t stop once you get the job. Be similarly prepared to advocate for yourself at your next performance review to get the raises and promotions that you deserve. “Having these conversations with your manager upfront and frequently is important,” said Fitzgerald. “If you don’t ask, you don’t get.”