How to Check References

Welcome back. This is part two of my series on checking references. Part one covers why checking references is important; now, let’s get into the details of how to go about conducting a reference check.

Check references late — after you’ve decided to make an offer

Reference checks are typically conducted very late in the hiring process, after you’ve decided to make an offer. You might do them after an offer is accepted — it’s not uncommon to have offer letters contingent on an acceptable reference check. My preference is to conduct reference checks in parallel with compensation negotiation: once I’ve decided to make an offer to a candidate, I’ll send them a tentative offer and ask for references at the same time. The underlying message I’m trying to send is: “we think you’re a great fit, want to have you on the team, and expect that your references will confirm that.”

Why check references so late? Well, one reason is that checking references can be time-consuming, so doing it for more candidates than the one you want to hire is wasteful. They also don’t tend to turn up enough information to help differentiate candidates – they’re more of a safety net than selection criteria. But the main reason is to be fair to candidates: reference checks carry some risk to the candidate. There’s always a risk that someone’s reference will leak the fact that your candidate is looking, and that could jeopardize their current employment. It’s unfair to expose someone to that kind of risk if you’re not pretty dang sure you’re going to hire them.

Ask for 2-3 references, and ask how they prefer to be contacted

When you ask your candidate for their references, here’s what to do:

Ask for two or three references. Two is good, three is plenty. One is fine if the candidate is fairly junior, but might be a red flag if a candidate has a very long work history but can only produce a single reference. A red flag isn’t necessarily a disqualifier, but it might be. The next part in this series will cover what to do if you see a red flag like this.
Ideally, at least one reference should be a manager. This isn’t always possible – there are a lot of bad bosses out there, so have some compassion if your candidate doesn’t have any former managers they’d trust to give a fair reference. But you should at least ask for one or more managers. If you don’t get any managers, that’s a possible red flag. Again, stay tuned for the next part for details on what do with red flags during a reference check.
Ask for phones and emails, and how the reference prefers to be contacted. Sometimes, candidates will prepare their references so they’re expecting a phone call; this can make logistics easy. Other times, references will want to be contacted by email first (or not by phone at all). If you’re not sure, or if you don’t get phone numbers, start with emails.
Try to get personal emails. If a candidate provides you an email address that’s pretty clearly a reference’s work email, see if you can get a personal one instead. You don’t know what email retention rules that person’s workplace has, and you may not want their reference check ending up “on the record” in that way.
Don’t expect references from the candidate’s current employer. As I wrote above, reference checks carry some risk to the candidate, and that risk is highest at their current employer. So many candidates will choose not to include any references from their current job. It’s certainly great to get to speak to someone who’s working with the candidate right now, but you can’t expect it, and shouldn’t think negatively of a candidate who only gives references from past employment.

Prefer phone/video calls to email for reference checks

It’s better to talk to a reference on a phone or video call than to interview them over email. People will almost always be more forthcoming when speaking than in writing, and it’s far easier to ask follow-up questions and have a real conversation on a call.

I’m a huge hypocrite here: I have an almost pathological distaste for phone calls, and often the overhead of setting up a video call feels like too much. I’m a bit ashamed to admit that I don’t always follow my own advice here. Sometimes I don’t have the energy for anything more than an email.

You should try to do what I say and not what I do — aim for phone/video calls, rather than email. But if you, like me, just can’t always make that happen it’s OK: something is better than nothing.

Remember that the reference is doing you a favor

When you contact a reference for a check, remember that they’re doing a favor – two favors, actually, one for the candidate and one for you. There’s nothing in it for them (except maybe a bit of a good feeling), so approach them with that in mind.

This means making things as easy and convenient for the reference as possible. Specifically:

Ask for a phone/video call if you can, but if they say they’d prefer to answer questions over email, do that instead. Don’t try to force them into doing things “your way”. Likewise, if you’d prefer video but they want phone (or vice versa), let them dictate that.
Let them choose the time. Don’t send a booking link (e.g. Calendly); don’t insist on a specific time. Ask them when a good time is and then make that time work on your end.
Make it quick. If you do a call, don’t spend more than 15-20 minutes. If it’s questions over email, 5-7 short questions are all you should realistically ask.

Questions to ask during a reference check

Reference checks are a kind of an interview, so just like interviews, you shouldn’t wing it. Have a set of questions you plan to ask. Over time you’ll probably develop your own script and preferences; there’s plenty of room for individual preference here. As a starting point for your scripts, here are the questions I almost always use:

“In what capacity did you work with them?”: A basic question to establish whether you're talking to someone's manager, peer, etc. Just a quick calibration for the remaining steps, so you know the context to ask about.
“What were their core job duties?”: Another calibration question, making sure that you understand the basics of their job before you ask more questions. Also a high level integrity check: does the answer the reference gives you match what the candidate put on their resume and/or told you about this job?
“What were their strengths?” / “What did they do well?”: (Two different ways of asking the same question, depending on how formal I'm feeling.) Like a retrospective, start with the good stuff to try to help people relax. It's also pretty rare for references to say anything negative, at least not directly. But if someone can't list many (or any!) strengths, that's bad. And you can sometimes infer weaknesses from strengths: for example, if a reference tells you that the candidate is great at getting new projects kicked off, that might imply they aren't as good at finishing. (You should follow up and ask!)
“What did they need to improve upon? Did you see them improve?”: I find outright asking about weaknesses to be difficult: many references will be reluctant to say something bad. I've found this formulation, talking in the past tense, is the best way of getting at what someone might not have done well. I'm less interested in weaknesses directly than I am in learning if they were able to make improvements. Most weaknesses aren't that bad as long as the person can work on them over time.
“How would you describe their relationships with their colleagues?”: This is the “working well with others” check. Listen carefully here: if the reference says things like “they mostly worked alone” or “they kept their head down”, that *might* be a sign of something worse. Also, pay attention to pauses: if the reference thinks for a long time before answering, that's quite possibly a problem.
“Would you [hire/work with] them again?”: The one million dollar question. If you could only ask one question of a reference, it should be this one. “I would work with them again" is a strong recommendation, much stronger than "you should hire them.” Once again, listen very carefully here. If the reference has to think about it, if they're not sure, there's something potentially bad there. Listen for hedging or someone who doesn't directly answer. You want to hear an unequivocal “yes” — or, better, a “hell yes” — here.
“Is there anything else you think I should know about them?”: 99% of the time the answer to this question is “no, they're great, hire them.” But the other 1% ... that's when the reference pauses, debates saying the thing that's been on their mind the whole call, and finally says "well yes, you need to know that ..." and tells you the scary thing that makes you rethink hiring them. Always leave space at the end for that to happen; it's the moment that'll save your butt.

For more potential questions you could add to your script, see OPM’s Reference Checking guide (PDF) - it’s quite good.

Up next: what to do if you spot a red flag?

Most of the time, the reference check will go well. You’ll call the reference, they’ll say glowing and wonderful things about your candidate, and you’ll leave the call with additional confirmation that you’re hiring the right person.

(This might be one of the reasons that the “you don’t need to check references” meme spreads: if you’ve only hired a handful of people, you might have only experienced positive reference checks. That can lead to the perception that they’re pro forma, and so why do them?)

Sometimes, though, something goes sideways. Maybe the reference won’t answer any questions, only confirm dates of employment. Maybe they tell you the person was fired for harassing a colleague. Maybe they tell you they don’t even know this person and have no record of them working there. These are all things that have happened to me!

I’ll talk about what to do if something like that happens in the next and final part of this series. Stay tuned.