Most of them sound innocent. They come up naturally in interview conversations. The person asking usually has no bad intent. They want to make small talk, understand context, or assess fit. None of that matters. Some questions are illegal to ask in the United States regardless of intent, and asking them can expose your company to discrimination claims.

This article covers what to avoid, why it matters, and the legal alternatives that get you the information you actually need.

A disclaimer up top. This isn't legal advice. Employment law varies by state, city, and federal jurisdiction, and the specifics evolve. The principles here are sound but you should consult an employment lawyer for guidance on your specific situation, especially as your company grows.

Why this matters more than people think

Three reasons companies should take this seriously.

Legal exposure. Discrimination claims based on interview conduct are real, and they're won. A candidate who can show they were asked about their family plans or religious practices, and then not hired, has the basis for a claim. Even if you'd never have used that information against them.

Bias in hiring decisions. Even if no claim is ever filed, asking off-limits questions changes how interviewers evaluate candidates. Information about family, age, or background leaks into decisions whether you intend it to or not. Structured hiring is supposed to prevent this. Bad questions undermine the structure.

Damage to candidate experience. Candidates who get asked about their immigration status, their kids, or their age remember it. They tell their friends. They post about it. The reputational cost can outlive any individual hire.

The good news: the questions to avoid are mostly well-defined, and the legal alternatives are usually clear. Read once, train your interviewers, and you've covered most of the risk.

Protected characteristics in the US (federal level)

Under federal law, you can't make hiring decisions based on these characteristics. Many states and cities add more.

Race or color
Religion
Sex (including pregnancy, sexual orientation, and gender identity)
National origin
Age (40 and over)
Disability
Genetic information
Citizenship status (with some exceptions for federal contracts)

Questions that probe these areas are off-limits, even if the candidate volunteers some of the information.

A common misconception: "If they bring it up first, I can ask about it." Not really. Even if the candidate mentions their kids, their religion, or their age, you should not follow up with questions that probe further. Acknowledge it briefly and move on.

Questions to never ask, by category

The list below isn't exhaustive but covers the most common traps.

Age and life stage

Don't ask:

How old are you?
When did you graduate from high school?
When did you graduate from college? (This is a soft proxy for age and risky.)
How long do you plan to work before retiring?
Are you a digital native? / Are you tech savvy for your generation?

Ask instead:

Tell me about your education and training relevant to this role.
What are your long-term career goals?
Walk me through how you stay current with [relevant tools/skills].

Family and personal life

Don't ask:

Are you married? Do you have kids? Are you planning to have kids?
Who's going to take care of your children while you work?
Are you single? Divorced?
How does your spouse feel about you taking this role?

Ask instead:

Are you able to travel for this role? (If travel is required.)
This role requires occasional weekend work. Can you commit to that schedule?
Is there anything that would prevent you from being available during our standard work hours?

The key distinction: you can ask about job-relevant availability and constraints. You can't ask about the personal circumstances that might affect them.

National origin and citizenship

Don't ask:

Where are you from originally?
What's your nationality?
What's your first language?
Where were your parents born?
Are you a US citizen?

Ask instead:

Are you authorized to work in the United States?
Will you require sponsorship for employment now or in the future?

Citizenship specifically: the law allows you to ask whether someone is authorized to work in the US and whether they'll need sponsorship. It doesn't allow you to ask about citizenship specifically.

Religion

Don't ask:

What's your religion?
Do you observe any religious holidays?
Will you need time off for religious observances?
Do you go to church?

Ask instead:

Are you able to work [the standard schedule]?
This role requires occasional weekend work. Can you commit to that schedule?

If a candidate later requests religious accommodation, you'll address it then. You can't pre-screen for it.

Disability and health

Don't ask:

Do you have any disabilities?
What medications are you on?
How many sick days did you take in your last role?
Have you ever filed a workers' compensation claim?
Have you ever been treated for a mental health condition?

Ask instead:

Can you perform the essential functions of this job with or without reasonable accommodation? (After describing the functions.)
Is there anything we should know about how to make this interview process accessible to you?

The Americans with Disabilities Act (ADA) is specific here. You can ask whether a candidate can do the job. You can't ask about the underlying conditions.

Race and color

Don't ask:

What's your ethnic background?
What does your last name mean? (When it's an attempt to identify ethnicity.)
Where did your family come from?

Ask instead:
Stick to the work. There's no legitimate reason to ask about race in an interview.

Sex, gender, and sexual orientation

Don't ask:

Are you a man, woman, non-binary? (Unless they've voluntarily shared.)
Do you identify as LGBTQ?
Are you pregnant? Are you planning to become pregnant?
What was your maiden name?

Ask instead:
Again, stick to the work. If you need preferred name and pronouns for the interview, ask in a structured way alongside accessibility needs.

Arrest and conviction records

Don't ask:

Have you ever been arrested?

Ask carefully:

Have you been convicted of a crime? (Many jurisdictions limit when and how this can be asked. Some require it only after a conditional offer. Check your state and city.)

"Ban the box" laws are common and growing. Many cities and states prohibit asking about conviction history before a conditional offer. Even where it's allowed, you can only consider convictions that are relevant to the role.

Salary history (in many places)

Don't ask (in many states/cities):

What's your current salary?
What did you make at your last job?

Ask instead:

What are your salary expectations for this role?
The compensation range for this role is X to Y. Does that work for you?

Salary history bans are now law in California, New York, Washington, Massachusetts, and many cities. Even where it's legal, it's a bad practice. It anchors offers to a candidate's past, which often reflects historical bias.

Edge cases that trip up interviewers

A few situations where well-meaning interviewers slip up.

Small talk at the start of an interview. "Tell me a bit about yourself outside of work" sounds friendly. It also invites candidates to share information that's off-limits. Keep the opening focused on the role and the conversation, not personal life.

Asking about gaps in employment. You can ask what someone did during a gap. You can't ask "did you have kids?" or "were you dealing with a health issue?" If they volunteer the reason, acknowledge it briefly and don't probe.

Asking about university experience. "Tell me about your time at [university]" can lead into questions about Greek life, sports, religious organizations, or other affiliations that touch protected characteristics. Stick to "what did you study and how does it connect to this role."

Comments about names. "What an interesting name, where's that from?" is a question about national origin even though it sounds like compliment.

Inviting the spouse to interviews. Some companies still do final-round dinners with the candidate's spouse. This invites discrimination claims and reveals information about family status. Don't.

What to do if a candidate volunteers off-limits information

This happens often. A candidate mentions their kids, their religion, their age, or their immigration status, unprompted.

What to do: acknowledge briefly, then redirect.

Example: A candidate says "I just got back from maternity leave."
Bad response: "Oh, how was your leave? When did you have your baby?"
Good response: "Welcome back. So, walk me through your most recent project."

You can be human. You don't have to ignore what they said. But don't ask follow-up questions that go deeper into the off-limits territory. Acknowledge, redirect to the work.

Document it briefly in your notes: "Candidate mentioned X. I redirected to the role." This protects you if questions come up later about how the information was handled.

Train your interviewers

The biggest source of risk isn't the experienced recruiter who knows the rules. It's the line manager or peer interviewer who hasn't been trained.

Three things to put in place:

A short training, refreshed annually. Cover the off-limits questions, the legal alternatives, and how to handle volunteered information. 30 minutes is enough.

A reference sheet they can use during interviews. A one-page document listing the questions to avoid and the alternatives. Put it in your interview guide.

Clear escalation for tricky moments. If an interviewer is unsure whether to ask something, give them a clear person to ask before the interview, not after.

The combination of training, reference material, and access to help eliminates most issues. Most problems happen because the interviewer didn't know any better.

What to do if you've already asked something you shouldn't have

Things happen. An interviewer asks something they shouldn't. You realize it after the fact. What now?

A few practical steps:

Document what was asked and what was said. Internal note, not shared with the candidate.

Don't let the off-limits information influence the hiring decision. Easier said than done. The structured interview scorecard helps here. Score on the actual competencies, not on impressions that include the off-limits information.

If the question was particularly serious or if a candidate raises a concern, talk to your employment counsel. Better to over-communicate with a lawyer than under-communicate after the fact.

Update your training so it doesn't happen again. One mistake becomes a pattern if you don't address it.

A note on structured interviews

The single best protection against asking the wrong questions is a structured interview process.

Same questions for every candidate. Pre-written, reviewed for legality, and built into a guide. Interviewers stay on script. Spontaneous "let me ask you something else" questions are where most off-limits questions come from. Structure prevents that.

For more on building structured interviews, see What Is a Structured Interview? (And Why It Makes Hiring Better) and How to Write an Interview Guide (With a Free Template).