Customer interview questions: 20 to ask and 6 to avoid

The most useful customer interview questions are about what a person has already done, not about what they think or might do. Ask about one specific past event, the workaround they use today and what it costs, how they chose their current solution, what happens when the problem is left alone, who else is involved and what they have already tried. Skip "do you like the idea?" and "would you buy it?": they get you politeness, not evidence. Below: 20 questions to copy, a table of bad questions with better replacements and a prep checklist.

The case: CatChow explores a subscription

CatChow, an online pet-food shop, is considering a subscription: food arrives on schedule, a little cheaper than a one-off order. Sofia, the product manager, calls ten cat owners and asks whether a subscription is a good idea, whether they would sign up and how much they would pay.

Nine of the ten say they would subscribe. A week later Sofia sends all ten a link to a pre-order page. One person pre-orders.

Nobody lied. The questions were about Sofia's idea and about the future, and agreeing with either costs nothing. So she rewrote the list around three rules for questions that get honest answers: keep the conversation on the person's own life and leave your idea out of it, ask about particular events that already happened, and spend most of the call listening. The new list doesn't mention the subscription once.

Customer interview questions, grouped by purpose

The wording is CatChow's. To reuse a question, replace "cat food" with your own problem area.

1. Past behaviour

1. "When did you last buy cat food? Tell me how it went, from the moment you noticed the bag was nearly empty."
2. "And the purchase before that one: was anything different?"
3. "When did buying food last not go to plan? What did you do?"

Why it works: a real event has a date, a place and a price, so it is hard to embellish.

2. The current workaround and its cost

4. "What do you do today so that the food doesn't run out?"
5. "How much did you spend on cat food last month, including delivery and extra trips?"
6. "How long did the last purchase take you, door to door?"

Why it works: people build workarounds only for problems that bother them, and the cost of a workaround is what your price will be compared with.

3. How they found and chose what they use now

7. "Where did the last bag come from? How did you first hear about that shop?"
8. "What made you pick it over the other options you knew about?"
9. "Have you ever changed where you buy food? What triggered it?"

Why it works: you hear the real purchasing criteria (price, distance, a brand always in stock) and where people discover things, which is where your marketing has to show up.

4. What happens if the problem is not solved

10. "The last time the food ran out, what happened next?"
11. "What did that cost you in money and time?"
12. "How many times has it happened in the last three months?"

Why it works: it separates a problem people pay to fix from an annoyance they live with. "I pop downstairs, it takes ten minutes" is a useful answer too.

5. Who else is involved

13. "Who in your home bought the last bag, and whose card was it?"
14. "Who has a say in what the cat eats: a vet, a partner, someone else?"
15. "When you last changed the food or the shop, who did you talk it over with?"

Why it works: the person in front of you is not always the one who decides or pays. In B2B this group matters most.

6. What they have already tried

16. "What have you tried so far to make buying food easier: delivery, an app, buying in bulk, reminders?"
17. "Which of those did you give up, and why?"
18. "Have you looked for a better option in the last few months? Where did you look?"

Why it works: someone who has never searched for a fix is unlikely to go looking for yours. Abandoned attempts show what your product must not repeat.

Two questions to end with

19. "Do you know anyone else who struggles with this? Would you put us in touch?"
20. "What should I have asked about but didn't?"

The first brings the next conversation; the second shows what you missed.

What one good answer looks like

Hannah, one of the owners in Sofia's second round, answered questions 4 and 10–12 with a story. She buys a 7 kg bag for 42 dollars, which is 6 dollars per kilo. Twice in the last three months the bag ran out before she had bought a new one. Both times she took a taxi to a supermarket and bought a 1.5 kg bag for 13.50 dollars, or 9 dollars per kilo: 50% more than she normally pays.

So running out costs Hannah 19 dollars and 80 minutes a quarter. That is what a subscription competes with for her, and no "I'd definitely subscribe" carries as much information.

Four of the ten owners in the second round told a story like Hannah's. For the other six, running out meant a ten-minute walk to the shop downstairs. Ten conversations are not a statistic, but they showed Sofia which owners to talk to next.

Bad question, why it fails, better question

When the conversation drifts into the future

Even with a good list, people slide into opinions and promises. Warning words: "I would", "I will", "usually", "always". Don't argue; bring the conversation back to one real event:

Hannah: I'd definitely use something that delivers automatically.

Sofia: Have you tried getting cat food delivered before?

Hannah: Once. The courier came while I was at work and the parcel went back. I never ordered again.

• A promise ("I would…"): ask whether they have ever done it. "When did you last…?"
• Praise for the idea: say thanks and return to facts. "How are you handling it this month?"
• A feature idea ("you should make an app…"): treat it as a clue and ask what it would let them do. More in the lesson on feature requests and digging.
• "So what are you building?": answer truthfully in one sentence ("we're trying to understand how people buy pet food") and go back to their story.

Common mistakes

• Reading the list like a questionnaire. Six or seven questions are plenty for fifteen minutes. The best material comes from follow-ups such as "what happened then?"
• Asking only safe questions. "How old is your cat?" is honest and changes nothing. Include at least one question whose answer could hurt the plan; see scary questions.
• Zooming in too early. "What's your biggest problem with buying cat food?" makes people invent a problem. Start broad and narrow down once they raise the topic themselves.

Checklist before a conversation

1. Write down the three things you most need to learn from this type of person. At least one should make you nervous. More in your 3 big questions.
2. Pick six or seven questions from the list above that lead to those three.
3. Look up what you can: the CRM, analytics, notes from earlier calls. Save the conversation for what only the customer knows.
4. Prepare an opening line that doesn't mention your idea.
5. Choose the format. A five-minute chat is often enough to learn whether the problem exists; keep it casual whenever you can.
6. Plan your notes: exact words and numbers, written down right after the conversation.

Key takeaways

• Good questions are about the past and present; bad ones are about opinions and the future.
• The cost of the current workaround is your best pricing benchmark.
• When you hear "I would", ask "when did you last?"
• Prepare three learning goals and six or seven questions, not a script.

FAQ

How many questions should I prepare for a customer interview?

Three learning goals and six or seven questions that lead to them. You don't need every answer from every person.

Can I ask customers about price?

Ask what they pay now, not what they would pay. "What did you spend last month, and where?" gives a real number. The only fully reliable answer about a future price is money on the table, such as a pre-order.

Do these questions work for B2B interviews?

Yes. The groups are the same; change the wording. Group 5 becomes the most important: who approves a purchase like this, whose budget pays for it, and who can block it.

Practise on real transcripts

The free lesson bad questions vs good questions takes Sofia's first list apart and lets you rewrite it yourself, with AI feedback on your version. It is part of the free course Customer Development: Talking to Customers.