Illegal Questions to Not Ask When Doing a Reference Check
The illegal questions to not ask when doing a reference check are the same ones you cannot ask a candidate directly, because routing a question through a former employer does not make it legal. That single rule covers most of what goes wrong. The rest comes from a handful of specific laws: the ADA on medical and disability questions, GINA on family medical history, state salary history bans, ban-the-box rules on criminal records, and the FCRA if anyone other than you is making the calls. This guide covers what not to ask, what to ask instead, and how to keep the process consistent enough to defend.
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Disclaimer: This article is general information for employers, not legal advice. Federal, state, and local hiring rules differ and change frequently, and salary history bans, fair chance laws, and background check requirements are among the fastest moving areas in employment law. Have an employment attorney licensed in the states where you hire review your reference check process, and confirm current requirements with the EEOC, the FTC, and your state labor agency.
Last reviewed: September 2026.
The Rule That Covers Most of It
There is no single federal statute listing forbidden reference check questions. The illegality comes from the same anti-discrimination laws enforced by the EEOC that govern interviews, and those laws apply to how you gather information, not just where you gather it from.
So the working test is simple: if you could not ask the candidate, you cannot ask their former employer. Asking a reference whether a candidate has children is exactly as problematic as asking the candidate, and arguably worse, because it looks like you were trying to get the answer indirectly.
A second test is nearly as useful: can you tie the question to the job? Questions about performance, reliability, skills, and working relationships are job-related and safe. Questions about the person's life, health, family, or beliefs are not, no matter how casually they come up in conversation.
Questions About Protected Characteristics
These are off limits in any form, and the risk is not only in asking. If a reference volunteers this information, do not write it down and do not let it factor into the decision.
- Race, color, or national origin. Including where someone is from, their accent, or their first language, unless a specific language is a genuine requirement of the job.
- Religion. Including whether their beliefs affected their availability on certain days. If schedule coverage matters, ask about the schedule directly instead.
- Sex, pregnancy, sexual orientation, or gender identity. Including whether they took parental leave or plan to have children.
- Age. Graduation years, "how long until retirement," and "would they fit with a young team" are all age inquiries in disguise, and federal protection applies from 40.
- Disability or medical condition. Covered in more detail below, because this is where most employers slip.
- Genetic information and family medical history. GINA prohibits requesting it, which includes asking a reference about a candidate's family illnesses.
- Marital or family status. Who they are married to, whether they are a single parent, whether childcare affected their attendance.
- Citizenship. You can confirm authorization to work through the I-9 process. You cannot ask a former employer about someone's immigration status or national origin.
- Military status. Including whether service obligations caused absences, which USERRA protects.
The Medical and Attendance Trap
This is the most common way a well-intentioned reference call goes wrong, because the question sounds like an ordinary performance question.
"How many sick days did they take?" is not a neutral attendance question. The EEOC and FTC joint guidance on background checks is worth reading in full on this point. Before a conditional offer, the ADA restricts disability-related inquiries, and asking about sick leave usage can amount to asking whether someone has a medical condition. The same applies to questions about workers' compensation claims, injuries on the job, prescription medication, mental health, or any period of medical leave.
What you can ask is whether the person met the attendance requirements of the role and whether they were reliable about showing up and giving notice. That phrasing gets you the information you actually need, which is reliability, without asking why someone was out.
After a conditional offer, the rules loosen and medical inquiries become permissible if applied uniformly to everyone entering that job. Even then, reference calls are the wrong channel for it.
Salary History
There is no federal salary history ban. As of September 2026, roughly twenty states plus the District of Columbia prohibit private employers from asking about or relying on a candidate's past pay, with Virginia's taking effect July 1, 2026, and a separate set of cities and counties imposing their own rules. Published counts differ because some laws cover only public employers, so verify your specific states rather than relying on a number. Several of those laws close the obvious loophole directly: they bar employers from having a recruiter, staffing agency, or background check vendor ask on their behalf, and they specifically cover contacting a former employer to learn what someone earned.
So in a covered state, "what was their salary?" to a former employer is the violation, not a workaround for it. In the strictest states you cannot use the figure even if it is volunteered.
What remains available everywhere is asking the candidate what they are seeking, stating the range for the role, and confirming it fits. For verification purposes, keep reference requests to dates of employment, job title, and rehire eligibility.
Criminal History and Arrests
Two separate issues here. First, arrests are not convictions, and the EEOC's enforcement guidance on arrest and conviction records treats them very differently: the fact of an arrest does not establish that criminal conduct occurred. Asking about arrest records is a longstanding problem area because arrest rates differ across racial groups, which makes reliance on them a disparate impact risk.
Second, timing. As of 2026, ban-the-box and fair chance laws cover more than 37 states, the District of Columbia, and over 150 cities and counties, and they control when in the process criminal history can come up at all. These lists grow most legislative sessions, so check the states you hire in rather than assuming last year's answer holds. In Illinois, for example, employers generally have to wait until the applicant has been selected for an interview, or until after a conditional offer if there is no interview. Asking a reference about criminal history early in the process can put you on the wrong side of that timing even though you never put the question on an application.
Union Activity, Complaints, and Anything That Looks Like Retaliation
Asking whether a candidate was involved in union organizing, filed a complaint, reported a safety issue, or raised a discrimination claim is both legally dangerous and a reliable way to create a retaliation case. Protected activity does not become fair game because a previous employer is willing to talk about it.
The same applies to questions about whether someone filed for workers' compensation or took FMLA leave. If a reference volunteers any of it, end that thread of the conversation and do not record it.
When Someone Else Makes the Calls
If you use a third-party background check company or a consumer reporting agency to conduct reference or employment verification, the FCRA applies, and the FTC publishes the employer-facing version of these requirements, and it brings a procedure with it: a clear written disclosure that is a standalone document rather than a clause buried in the application, written authorization, and an adverse action sequence if the results lead you to reject the candidate. That sequence means a pre-adverse action notice with a copy of the report and a summary of rights, a reasonable window to dispute, commonly around five business days, and then a final adverse action notice naming the agency.
Two things employers miss. The FCRA can reach beyond full-time employees, including part-time staff, temporary workers, contractors, and sometimes volunteers, when the screening is for employment purposes. And using a vendor does not launder an illegal question. If your vendor asks about salary history in a state that bans it, that is still your problem.
Reference Check Questions That Are Legal and Actually Useful
- Can you confirm the dates of employment and job title?
- What were their main responsibilities?
- How did their performance compare to expectations for the role?
- Did they meet the attendance and punctuality requirements of the position?
- How did they work with colleagues, customers, and supervisors?
- How did they handle deadlines, pressure, or changing priorities?
- What kind of supervision brought out their best work?
- Were there any performance concerns raised with them during their time there?
- Is the person eligible for rehire?
- Is there anything else relevant to their ability to do this job?
How to Rephrase the Questions You Actually Want Answered
Most illegal questions are a legitimate concern wearing the wrong clothes. The concern is usually fine; the phrasing is the problem.
- Instead of "how many sick days did they take," ask whether they met the attendance requirements of the role.
- Instead of "do they have any health issues that affected their work," ask whether they were able to perform the essential functions of the job.
- Instead of "what was their salary," ask them to confirm dates, title, and rehire eligibility.
- Instead of "did childcare cause problems," ask whether they were reliable about scheduled shifts and gave notice when they could not make one.
- Instead of "would they fit with a younger team," ask how they worked with colleagues at different experience levels.
- Instead of "do they have a criminal record," follow your jurisdiction's timing rules and run a compliant background check at the right stage.
What Former Employers Will Actually Tell You
Expect limited answers. Many companies restrict references to dates, title, and whether the person is eligible for rehire, because saying more creates defamation exposure. That policy is why "eligible for rehire" is worth asking every time; it is the one short answer that carries real signal and that most HR departments will still give.
If you are on the answering side of these calls, the safe approach is to decide on one policy and apply it to everyone. Stick to facts you can document, avoid characterizations, and route anything beyond confirmation of employment through one person rather than letting individual managers improvise. Many states have statutes giving employers qualified immunity for good-faith references, but that protection generally depends on the information being truthful and job-related rather than malicious.
Common Mistakes
- Treating the reference call as off the record. A friendly, unstructured conversation is where the illegal questions get asked.
- Asking different questions of different candidates. Inconsistency is how a discrimination claim gets proved, even when no single question was improper.
- Writing down what a reference volunteers. Notes about someone's pregnancy or health become evidence that you knew and considered it.
- Letting a vendor ask what you cannot. Several salary history laws explicitly cover third parties acting on your behalf.
- Skipping the FCRA sequence. If a third party produced the report and you reject based on it, the pre-adverse and adverse notices are mandatory, not optional.
- Checking references for some candidates only. If you check finalists, check all of them, the same way.
Where a System Helps
None of this requires software. A written question list used identically for every candidate, with notes kept in the candidate's file, covers the substance of it.
What matters in any tool you use: the same structured questions presented for every candidate, notes stored on the candidate record rather than in a manager's notebook, and a hiring history you can reconstruct months later if a rejected applicant asks how the decision was made.
In Updoot, candidate records, scorecards, and interview notes live in the same place the hire eventually becomes an employee record, so the reference notes are attached to the process rather than scattered across inboxes, and the same evaluation structure is applied to everyone in the pipeline. The job description the role was posted under stays attached to it, which is what makes "job-related" a defensible claim rather than an assertion.
Frequently Asked Questions
Anything about race, national origin, religion, sex, pregnancy, sexual orientation, gender identity, age, disability or medical history, genetic or family medical information, marital or family status, citizenship, or military service. Salary history is prohibited in roughly twenty states plus DC, and criminal history questions are restricted by timing under ban-the-box laws in most states. The general rule is that if you could not ask the candidate directly, you cannot ask their former employer either.
No. Asking about sick leave usage can function as a disability-related inquiry under the ADA, which restricts such questions before a conditional offer. Ask instead whether the person met the attendance requirements of the role and was reliable about giving notice. That gets you the reliability information you need without touching medical territory.
Not in states with a salary history ban, which covers roughly twenty states plus the District of Columbia, with Virginia's effective July 2026. Several of those laws specifically prohibit contacting a former employer for pay information and bar using recruiters or background check vendors to ask on your behalf. Keep verification to dates of employment, job title, and rehire eligibility, and ask the candidate about salary expectations instead.
Do not pursue it, do not record it in your notes, and do not let it influence the decision. Redirect to a job-related question. Written notes documenting that you knew about a pregnancy, medical condition, or religious practice can become evidence in a discrimination claim even if you never asked about it, so the safest response is to move the conversation back to performance.
It applies when a third-party consumer reporting agency conducts the check for employment purposes. That triggers a standalone written disclosure, the candidate's written authorization, and an adverse action sequence if you reject them based on the results: a pre-adverse action notice with a copy of the report and a summary of rights, a reasonable dispute window of around five business days, then a final adverse action notice naming the agency. Checks you conduct yourself generally fall outside the FCRA, though discrimination law still applies.
Truthful, job-related information, though many companies limit responses to dates of employment, job title, and rehire eligibility to reduce defamation risk. Many states provide qualified immunity for references given in good faith, which typically depends on the information being accurate and not malicious. There is no general federal law restricting a former employer to dates and titles; that practice is company policy rather than a legal requirement.
Final Takeaway
Use one written list of job-related questions for every candidate, ask about performance and reliability rather than the person, keep salary history and criminal history out of the conversation unless your jurisdiction and stage clearly allow it, follow the FCRA sequence whenever a third party produced the report, and write down only what relates to the job. The consistency is what protects you. A rejected candidate rarely wins on a single bad question, but they often win on a process that treated two people differently.
Official Sources
- EEOC: Background Checks, What Employers Need to Know
- Federal Trade Commission: Background Checks, What Employers Need to Know
- EEOC: Enforcement Guidance on the Consideration of Arrest and Conviction Records
- EEOC: Employees and Applicants
- U.S. Department of Labor: Your Rights Under USERRA
- U.S. Department of Labor: Wage and Hour Division