Internal Auditor Interview Questions UK: 8 Real Questions and What Interviewers Want

Before your Internal Auditor interview, it helps to see the questions from the interviewer's side. We have picked eight from our set of 25 and added the reason each one gets asked.

Eight Internal Auditor interview questions, and what the interviewer is thinking

1. Walk me through how you carry out an internal audit assignment from start to finish.

Why they ask: This is the most common internal audit interview question and shows whether you work in a structured, standards-based way.

2. Why do you want to work in internal audit rather than external audit or a finance role?

Why they ask: They want to know you understand the purpose of internal audit and are genuinely interested in it.

3. How is a risk-based internal audit plan put together?

Why they ask: Mid-level auditors contribute to annual planning, so they want to see you understand how audit coverage is prioritised.

4. How do you write a strong internal audit finding?

Why they ask: Report writing is central to the role, and weak findings undermine credibility.

5. How do you decide on sample sizes when testing the operating effectiveness of controls?

Why they ask: Testing methodology is fundamental, and they want to know your conclusions are defensible.

6. How do you decide the overall assurance opinion for an audit report?

Why they ask: Assurance ratings drive the attention a report gets from the audit committee.

7. At follow-up, a manager tells you an agreed action has been implemented, but your testing shows the control still isn't working. What do you do?

Why they ask: Follow-up validation is critical to internal audit's value, and managers often overstate progress.

8. Tell me about an audit where your recommendations led to a real improvement.

Why they ask: They want evidence that you add value rather than just produce reports.

A sample answer to question 1

Walk me through how you carry out an internal audit assignment from start to finish.

It starts with planning. I'd meet the audit sponsor to understand the objectives of the area, the key risks and any recent changes, review policies, previous reports and risk registers, and agree a terms of reference covering scope, timing and reporting lines. Next comes fieldwork. I document the process through walkthroughs, map the key controls against the risks, and assess whether they're designed adequately. Then I test operating effectiveness, using sample sizes based on control frequency, or data analytics where the population allows. Exceptions are discussed with the process owner as I go, so nothing in the report is a surprise. I then draft findings with root causes and agreed actions, rate each one and give an overall assurance opinion. After a closing meeting, the draft goes to management for responses, owners and target dates before the final report is issued and summarised for the audit committee. Finally, actions are tracked and validated through follow-up.

Common mistake to avoid: Skipping the follow-up stage; Describing it as box-ticking

Want the rest?

Full model answers, key points and common mistakes for all 25 questions are on the Internal Auditor interview questions page. The first five are free, no sign-up needed.