7 mistakes you should never make during a job interview, according to a business-etiquette expert

• Business Insider asked an etiquette expert about the mistakes candidates make during job interviews.
• Many people forget to research the company and clean up their social media pages beforehand.
• Arriving on time and sending a thank-you note are easy ways to make a good impression.

For many, job interviews can be a nerve-racking experience. Even with proper preparation, it's common to struggle with this important step in the hiring process.

To help you avoid common mistakes, Business Insider asked business-etiquette expert Jacqueline Whitmore about the things candidates should avoid doing during an interview. Here's what she said.

Not coming prepared for the interview

Whitmore told BI that a simple but common mistake candidates make is arriving to the interview unprepared.

"Most people don't do the proper research about the company. We have so many resources to use, including LinkedIn, websites, and social media," she said. "There's no excuse for you to go into an interview and not know about the company and something about who might be interviewing you."

Whitmore also said it's important to ask the interviewer questions tailored specifically to the company.

Dressing too casually or overlooking small details

According to Whitmore, dressing too casually is another common mistake she sees interviewees make.

"Very rarely do we see someone overdressed for a job interview," she said. "They oftentimes don't put a lot of thought into the details, like the color of their belt or that their shoes are matching their outfit."

Whitmore told BI that even when candidates do wear office-friendly attire, they may overlook other key details, like forgetting to cut off the tags or not cutting open the vents in the back.

"Why would an employer want to hire someone who doesn't pay attention to the details?" Whitmore asked.

Forgetting to put their best foot forward on social media

Before stepping into a job interview, it's important to consider how you're presenting yourself online, especially since Whitmore said the first thing an employer will likely do is Google you.

"They'll look at all your social media pages. They'll look at what you eat, what you drink, what you wear, who you hang out with, what your lifestyle is — and they make judgments," she told BI.

For that reason, Whitmore suggested adjusting your privacy settings and cleaning up your social media presence to eliminate anything that could be used against you.

Using filler words, profanity, or slang

When in a job interview, Whitmore told BI that candidates should never use inappropriate language, such as profanity, slang, or terminology the employer might not understand.

She also said to be cautious of filler words and phrases such as "like" or "um" to avoid muddling the conversation.

Whitmore suggested recording yourself before the interview or practicing ahead of time to ensure you're speaking clearly and precisely.

Having your camera off during a virtual interview

One mistake to avoid in virtual interviews is refusing to turn your camera on.

Candidates may choose to keep their cameras off for a number of reasons, such as being worried about making eye contact or feeling uncomfortable with face-to-face interaction. However, Whitmore said keeping the camera on is a good idea so the employer can see your facial expressions.

She added that candidates should be wary of what their background looks like and make sure their room appears tidy.

"If you just have to have a blank wall, that's better than a huge distraction. But I definitely recommend that you put a little thought into your background," she said.

Arriving late to the interview

"Showing up late for an interview is a huge no-no," Whitmore said. "I've always said when you're on time, you're still late. You should show up early."

Arriving early ensures you have enough time to find parking or the meeting room. Whitmore added that doing so also allows you to use the restroom and gain your composure before the interview starts.

Not sending a thank-you note

Sending a thank you note is an important step in the interview process.

"I go overboard. I send a thank you email and a thank you note because this is an opportunity for you to get into the employer's eyes at least twice," Whitmore told BI.

Be sure to follow up within 24 hours of the interview and personalize the note.

"Address the person by name. Tell them why you enjoyed the interview and why you would be a good candidate," Whitmore said.

If you're feeling stuck, she suggested writing out a note and using an AI tool like ChatGPT to polish it.

This story was originally published on January 14, 2025, and most recently updated on January 23, 2026.