Customer interviews: a practical guide with 25 user interview questions

Customer interviews are short, structured conversations in which you ask users about their real past behaviour, problems and workarounds, so you can decide what to build without relying on opinions or guesses. The most reliable approach is to talk about the customer's life rather than your idea, ask about specific things that already happened, and listen far more than you speak. This guide covers how to recruit participants in India, a copyable interview script, 25 good user interview questions and a simple method for turning notes into decisions.

Key takeaways

• Ask about the past, not the future. "When did you last…" beats "Would you use…" every time.
• Never pitch during a discovery interview. The moment you describe your solution, people start being polite.
• Compliments, generic claims and feature requests are weak evidence. Specific stories, workarounds and money already spent are strong evidence.
• In India, recruit through your own users first, run interviews in the participant's preferred language and get clear consent before recording.
• Synthesise within a day: one observation per note, cluster, count, then write insight statements that lead to a decision.

What is a customer interview?

A customer interview (also called a discovery interview or user interview) is a one-to-one conversation, usually 30 to 45 minutes, aimed at understanding a person's goals, context, problems and current solutions, before or alongside building a product.

It is different from the other research tools you might reach for:

The best teams use them together: interviews to find the problem, surveys to size it, analytics to confirm behaviour, usability tests to check the solution.

The Mom Test: three rules for honest answers

The most practical framework for discovery interviews comes from Rob Fitzpatrick's book The Mom Test (2013). Its premise is that everyone, even your mother, will lie to you about your idea if you ask them the wrong way, usually to be kind. Fitzpatrick's three rules are:

1. Talk about their life instead of your idea. Ask how they handle the problem today, not what they think of your solution.
2. Ask about specifics in the past instead of generics or opinions about the future. "Tell me about the last time" produces facts. "Would you ever" produces optimism.
3. Talk less and listen more. If you are speaking for more than a fifth of the interview, you are pitching.

The book also names the kinds of bad data to watch for: compliments ("that sounds great"), fluff (generic claims like "I always", hypotheticals like "I would") and ideas or feature requests taken at face value. When you hear one, steer back to a concrete example. Fitzpatrick also argues that the real signal of interest is commitment: time, reputation or money the person is willing to give, such as agreeing to a follow-up pilot or introducing you to their manager.

How many customer interviews do you need?

Keep going until you stop hearing new things. For a single, well-defined segment that often happens after five to eight conversations; if you are still surprised after ten, your segment is probably too broad and should be split.

Two cautions. First, the widely quoted "test with five users" advice comes from usability testing, which checks a design, not from discovery, which explores a problem. Second, interview each segment separately. A Bengaluru startup founder and a Ludhiana textile trader may both "manage invoices", but their problems will have little in common.

How to recruit users for interviews in India

Recruiting is where most interview programmes stall. These channels work, roughly in order of effort:

1. Your own users. An in-app banner, a line in the order confirmation email or a call from support: "We're improving how payments work. Would you share 30 minutes about your experience?" Include churned and inactive users; they explain problems your fans will not.
2. Support tickets and reviews. People who have just complained are often happy to talk, because someone is finally listening.
3. Your network for B2B. LinkedIn messages, alumni groups, founder communities and introductions from existing customers (pre-launch founders, see Product Circle for founders). Ask every participant: "Who else should I talk to?"
4. Community and messaging groups. Housing society groups, trader associations and hobby groups, always with the admin's permission.
5. Field visits. For kirana stores, small restaurants, clinics or delivery partners, nothing beats visiting during a quiet hour. You will see the workarounds on the counter.
6. Recruiting agencies. Useful for consumer research at scale outside metros, at a cost.

Practical details that matter in India:

• Language. Offer the interview in the participant's preferred language and bring a colleague who speaks it if you do not. You will get shorter, flatter answers in a second language.
• Medium. Many participants are more comfortable on a phone call or a WhatsApp video call than on a scheduled video meeting link. Go where they are.
• Timing. Avoid festival weeks and month-end for business owners. Working professionals often prefer early mornings, lunch or after 8 pm.
• Beyond the metros. If your growth is in tier-2 and tier-3 cities, interviewing only colleagues' friends in Bengaluru, Mumbai and Delhi NCR will mislead you.
• Incentives. A thank-you such as a shopping voucher or a UPI transfer is standard for consumers; set the amount according to the time asked and the person's seniority. For B2B, a summary of what you learned is often more valued than money.
• No-shows. Confirm the day before and on the morning of the call, and book one or two more sessions than you need.
• Consent. Explain why you are talking to them, how notes will be used and ask before recording. India's Digital Personal Data Protection Act, 2023 makes consent and purpose limitation a legal question as well as an ethical one, so store recordings securely and delete what you do not need.

Use a short screener (three to five questions) to make sure you are talking to the right people, for example: "In the last month, how many times did you order groceries online?" Screen on behaviour, never on attitude.

A customer interview script template

Copy this and adapt it. The script is a guide, not a questionnaire: follow the story wherever it is most specific.

CUSTOMER INTERVIEW SCRIPT (30–40 minutes)

Before the call
- Goal: what decision will this research inform? [one sentence]
- Segment and screener criteria: [who qualifies]
- Roles: interviewer [name], note-taker [name]

1. Intro (2–3 min)
"Thanks for making time. I'm [name] from [company]. We're trying to
understand how people [do the job]. There are no right answers, and
nothing here is a sales pitch. Is it OK if we record this for our notes?
Only our team will hear it."

2. Context (5 min)
- Tell me a little about your role / your household and a typical [week].
- Where does [the job] fit into that?

3. The last time (15–20 min)  <- the heart of the interview
- Tell me about the last time you [did the job]. Walk me through it.
- What happened just before that? What happened next?
- What was the hardest part? Why?
- What did you try? What did it cost (time, money, effort)?

4. Current solutions (5–8 min)
- What do you use for this today? How did you choose it?
- What do you wish it did differently? What did you do about that?

5. Priority and commitment (3–5 min)
- Where does this rank among the things you're trying to fix right now?
- Would you be open to trying an early version and giving feedback?

6. Wrap-up (2 min)
- Is there anything I should have asked but didn't?
- Who else do you know who deals with this?
- Thank them; confirm the incentive and how it will be sent.

After the call (within 30 minutes)
- Top 3 surprises
- Strongest quote (verbatim)
- Evidence of commitment, if any

25 good user interview questions

Use these as a bank, not a list to read out. Six to ten questions plus follow-ups fill a 40-minute interview.

Throughout, the most useful follow-ups are the shortest: "Tell me more about that." "Why?" "What happened next?" "Can you show me?" And then silence. People fill a pause with the detail you need.

Bad vs good customer interview questions

How to run the interview itself

1. Interview in pairs. One person asks, the other takes notes. Swap roles on the next call.
2. Start broad, then go specific. Context first, then the last time, then details.
3. Chase the strongest emotion. When someone sighs, laughs or says "honestly", ask more.
4. Ask to see it. A screen share of their spreadsheet, a photo of the register, the WhatsApp group they use with suppliers. Artefacts do not exaggerate.
5. Do not correct or teach. If they use your product "wrong", that is data.
6. Hold the pitch. If they ask what you are building, offer to show them at the end, briefly.

These skills transfer. Asking open, specific questions is just as useful in an AMA (see how to ask good questions in an AMA) or a networking conversation.

How to synthesise customer interviews

Synthesis turns a pile of notes into a decision. A lightweight method that works for most teams:

1. Debrief within a day. Each interviewer lists surprises, quotes and evidence of commitment.
2. Break notes into atomic observations. One fact, quote or behaviour per sticky note or spreadsheet row, tagged with the participant ID.
3. Cluster by theme. Group similar observations (an affinity map). Name each cluster in the user's words, not your team's jargon.
4. Count. For each theme, how many participants mentioned it, and how strongly? "7 of 9 reconcile payouts manually every week" is an insight; "some users mentioned payouts" is not.
5. Write insight statements. Use a consistent format: "[Segment] struggles to [job] because [cause], which costs them [impact]. Evidence: [n of m participants, key quote]."
6. Map insights to opportunities. Teresa Torres's opportunity solution tree, from her book Continuous Discovery Habits, is a good structure: outcome at the top, customer opportunities beneath it, then candidate solutions and the experiments to test them.
7. Decide. Each insight should lead to an action: build, test, research further or drop.

A simple synthesis table keeps everyone honest:

From here, size the strongest opportunities, score them with a prioritization framework and write the problem statement and evidence into your PRD. Interview insights are also how you find the value moment behind a good north star metric.

Common customer interview mistakes

• Interviewing only friendly users or colleagues.
• Asking leading or hypothetical questions, then treating the answers as validation.
• Recording everything and synthesising nothing.
• Stopping after one round. A few conversations every week beats one big study a year.

Frequently asked questions

What are the best user interview questions?

The best questions ask about specific past behaviour: "Tell me about the last time you…", "What was the hardest part?", "What did you try?" and "What did it cost you?". Avoid questions about the future or about your idea. Use the 25 questions above as a bank and follow the most specific story.

How long should a customer interview be?

Thirty to forty-five minutes is enough for most discovery interviews. Shorter calls rarely get past surface answers; longer ones tire participants. For field visits to shops or offices, fifteen focused minutes at a quiet time can be more valuable than an hour on video.

What is the Mom Test in customer interviews?

The Mom Test is a set of rules from Rob Fitzpatrick's 2013 book for getting honest answers even from people who want to be nice to you. Talk about their life instead of your idea, ask about specifics in the past instead of opinions about the future, and talk less and listen more.

Should you pay participants for customer interviews?

For consumer interviews, a small thank-you such as a voucher or UPI transfer is common and improves show-up rates. For B2B interviews, many professionals decline payment but appreciate a summary of findings. Whatever you offer, state it upfront and send it promptly.

Keep the habit going

Customer interviewing is a skill you build by doing it often and comparing notes with others who do the same. Product Circle brings together 250+ PMs and founders who trade exactly these kinds of lessons, and new members are introduced with a one-line tagline so it is easy to find someone working on a similar problem. Read more about member intros, or see how to join.

• Customer interviews
• User research
• Product discovery