'Tell Me About a Time You Made a Mistake': STAR Answers for Finance Roles

"Tell me about a time you made a mistake" is a test of what you did after the mistake, not of whether you've ever made one. Pick a real, moderate error from your own work, own it in one sentence, spend most of the answer on how you found it, fixed it and told the right people, and finish with the check you now run so it doesn't happen again. Below: what finance interviewers are listening for, how to choose your mistake, and four hypothetical STAR answers for accounting, FP&A, audit and treasury roles.

Key takeaways

• The question tests what you did after the mistake: disclosure, fix and learning.
• Choose a real, moderate error you caught and fixed, ideally not in the core skill of the job you're applying for.
• Keep the mistake to one sentence and spend most of the answer on your actions.
• End with a specific check or habit you still use, not 'I learned to be more careful'.
• Never borrow a story or invent figures; interviewers will ask follow-up questions.

What are finance interviewers testing with this question?

Everyone makes mistakes with numbers. The interviewer wants to know three things: whether you'll tell them, whether you can fix it properly, and whether you learn.

In finance, that maps closely onto professional ethics. ACCA's fundamental ethical principles start with integrity, defined as being "straightforward and honest in all professional and business relationships", and include professional competence and due care, which means acting "diligently and in accordance with applicable technical and professional standards". A mistake story lets you show both: you were honest about the error, and you put in a control afterwards.

It's also a standard competency question. targetjobs lists "What has been your biggest failure?" among common competency questions, and its STAR guidance says the result should show "you in a good light, even if the overall project was not a success." Prospects lists resilience among the competencies employers regularly seek, and a recovered mistake is one of the clearest ways to show it.

What they're listening for, in order:

How do you pick the right mistake?

This is where most candidates go wrong. They either choose something so small it isn't a mistake ("I sometimes work too hard") or something that raises doubts about their judgement.

A good mistake for a finance interview

• Real and yours. It happened, and you were responsible. Don't borrow someone else's story.
• Caught, ideally by you. Errors you spotted before they caused damage make the strongest stories.
• Moderate impact. Something that needed correcting and explaining, but didn't cause a regulatory breach or a loss you can't account for.
• Has a lasting fix. You can name the check, template or habit you introduced.
• Not core to the job you're applying for. If you're interviewing for a payroll role, a story about a payroll error is risky. A spreadsheet or cut-off error elsewhere is safer.

Mistakes to steer away from

Avoid anything involving dishonesty, a confidentiality breach, a client complaint you mishandled, or an error you never fixed. Also avoid trivial examples. The interviewer has heard "I once sent an email to the wrong person" many times, and it tells them nothing about how you handle numbers.

If you're a graduate or career changer, a mistake from a placement, a part-time job or a university project is fine. The National Careers Service says examples "could be from work, home or volunteering". Its own model STAR answer is about a mix-up where flowers were delivered to the wrong venues. Just make the link to finance work clear.

How do you structure a mistake answer with STAR?

The National Careers Service defines the Result as "what happened as a result of your action and what you learned from the experience". For a mistake question, the learning is half the answer. Prospects goes further and adds a separate Reflection step (STARR): "What you learned from the experience and how it shaped you afterward."

A workable split for a two-minute answer:

1. Situation (1–2 sentences): the role and the task, briefly.
2. Task (1 sentence): what you were responsible for.
3. Mistake (1 sentence): what you got wrong, stated plainly.
4. Action (4–5 sentences): how you found it, who you told, how you fixed the number and the cause. targetjobs advises: "Proportionally, you should dedicate most of your response to the Action part."
5. Result and learning (2–3 sentences): the outcome and the specific change you made.

If you're still building your bank of stories, our post on STAR interview examples for finance covers the method in more depth, with audit, FP&A and risk answers for other competency questions.

Model STAR answers for finance roles

All four answers below are hypothetical examples, made up to show the structure. Don't use them as your own. Replace every detail with something that actually happened to you.

Accounting: a wrong accrual at month-end

Hypothetical example.

• Situation: I was an assistant accountant on a monthly close for a services business.
• Task: I prepared the accruals for unbilled supplier costs.
• Mistake: I accrued a contractor's monthly fee that had already been invoiced and posted through the purchase ledger, so the cost was counted twice.
• Action: I spotted it two days after close when the department's cost line looked high against its forecast. I traced the difference back to my accrual, then told my manager straight away, before the management pack went to the finance director. I posted a correcting journal in the current month with a clear narrative, and updated the variance commentary so the budget holder wasn't chasing a cost that didn't exist. Then I changed my accruals process: I now run a purchase ledger report for each supplier before accruing, and tick off anything already invoiced.
• Result: The pack went out with the correction explained. My manager added the purchase ledger check to the team's close checklist. I learned to check what's already in the ledger before adding to it.

FP&A: a broken link in the forecast model

Hypothetical example.

• Situation: I was a finance analyst preparing the quarterly reforecast.
• Task: I owned the headcount cost tab, which fed the overall forecast.
• Mistake: When I added rows for new starters, one formula didn't pick up the new range, so part of the payroll cost was missing from the total.
• Action: I found it when I reconciled the forecast's payroll line to the HR headcount report, which showed more people than my model. I told the FP&A manager before the numbers went to the budget holders, fixed the range, and re-ran the summary. I then added a check row that compares headcount in the model to the HR report and flags any difference, and I documented the tab so anyone adding rows knew which ranges to extend.
• Result: The reforecast went out corrected and on time. The check row has stayed in the model. I learned that every model needs a reconciliation back to a source outside the model.

For FP&A CV lines that show this kind of control work, see our FP&A CV examples.

Audit: a sample selected from the wrong population

Hypothetical example.

• Situation: I was a first-year audit associate testing purchases on a year-end audit.
• Task: I had to select a sample of invoices from the full-year purchase listing.
• Mistake: I selected from a listing the client had sent that turned out to cover only the first eleven months.
• Action: I noticed when I reconciled the listing's total to the trial balance and it didn't agree. I told my senior the same afternoon rather than waiting until review. We agreed I'd request the full-year listing, reconcile it to the trial balance first, and reselect the sample. I documented what had happened on the file so the reviewer could follow it.
• Result: The testing was completed within the fieldwork window. I now reconcile every population to the trial balance before I select a sample from it.

Treasury and operations: a payment on the wrong date

Hypothetical example.

• Situation: I worked in a treasury operations team processing supplier and intercompany payments.
• Task: I prepared the payment file for approval each week.
• Mistake: I set the value date on one intercompany payment a day early, which left a subsidiary's account short for a day.
• Action: The cash position report flagged the overdraft the next morning. I told my team lead, checked whether any charges had been incurred, and arranged an internal transfer to correct the position. I then added a step to my file preparation: I compare every value date to the payment schedule before submitting the file for approval.
• Result: The position was corrected the same day. The team adopted the value date check for all payment files. I learned to check dates as carefully as amounts.

Notice what none of these answers include: invented figures. If your real version has a value, give it only if you can explain where it came from. It's the same rule we follow in our own finance career notes.

What mistakes should you avoid in your answer?

• The disguised strength. "I'm a perfectionist" isn't a mistake. Interviewers spot it straight away.
• Blame. "The system didn't flag it" or "my manager gave me the wrong file" undoes the ownership you're meant to show. Mention context, then own your part.
• A hypothetical answer. Prospects warns against "abstract or hypothetical responses" and advises against saying "I would usually…". Tell a story that actually happened.
• No fix to the cause. Correcting the number is half the job. The interviewer wants the control you added.
• Vague learning. "I learned to be more careful" isn't a lesson. "I now reconcile the population to the trial balance before sampling" is.
• An unrehearsed follow-up. The National Careers Service says to "be prepared to answer follow-up questions about the examples you give." Expect "What would you do differently?" and "How did your manager react?"

How should you prepare your mistake story?

Write it down in STAR form, then read it aloud and time it. Under two minutes is a good target. Check every detail against your CV, because the interviewer will often have it open, and a story that doesn't match a CV line invites questions.

Then prepare a second mistake story. Some interviewers ask for another example, and a backup stops you reaching for something weaker on the spot.

The best mistake answers are short on the error and long on the fix. As a next step, look at the duties on your current CV and ask which one you once got wrong and then improved. That's usually your story. If you want to check those CV lines hold up first, upload your CV to the Coffee & Excel workspace and confirm what's accurate before you rehearse.

Frequently asked questions

Is it OK to say I've never made a mistake at work?

No. Everyone makes mistakes with numbers, and saying you haven't suggests either a lack of self-awareness or a lack of honesty. Pick a real, moderate one you fixed.

Can I use a mistake from university or a part-time job?

Yes, especially as a graduate or career changer. The National Careers Service says STAR examples can come from work, home or volunteering; just make the link to finance work clear.

How long should my answer be?

Aim for under two minutes. Keep the situation and the mistake brief and give most of the time to what you did about it.

Should I mention how much the mistake cost?

Only if you know the figure and can explain where it came from. If you can't, describe the impact in words instead.