Internal Audit Team - The number of internal auditors a company should have



Is there a standard or a recommendation regarding the number of internal auditors a company should have? For instance a company of 1000 employees should have an audit team of X members? (Or, given full-time and part-time auditors X hours of audit hours per month?)

I have looked at ISO 10011-1 and cannot find anything. I also have not been able to get a response from RAB.

Does anyone know if there is a guideline, what it is or where I can find it?

Thank you in advance.

Elsmar Forum Sponsor


Fully vaccinated are you?
There's no standard requirement. It depends upon your company needs and how you want to structure things. You could have 1 auditor who only audits. Or you could have 50 auditors who each audit once a year.

I'm sure you will get some replies from others who have come up with a 'rule of thumb' for their comnpany - but again be warned - what is right for 1 company isn't always right for another.
There is no rule of thumb regarding the number of internal auditors, but in an article in Quality online I read that Dan Bridget (Lead Assessor) estimated that for a company employing 100 - 300 people, 10 - 12 internal auditors should cover it, other articles I have read elsewhere mention anything from 1 per 50 employees to 5 for medium sized manufacturing plant, so all things being equal it really depends on the size and complexity of your operation and the experience and time availability of your internal auditors.



Is my point of view that despite of there is no place where a written rule is given related this topic, is not covenient having only ONE internal Auditor, because..Who will audit s/he ?.

If I were you probably would apply the rule of having from 3 to 5 folks for a micro/small company, less than 50 souls and 5 to 10 folks for a medium sized company,let's say less than 200. For bigger plants it is really a matter of making numbers.

I have 2 more points of view :

1) If you have a very limited number of auditors (supose 2 or 3) you have the risk that they would have another urgent duties related their own activities during the week of the audit,hence the importance of having enough people (not to many of course)in order to face that kind of emergencies.

2) I am convinced that in the case of companies that have the problem that the majority of people is not awere or convinced to change their attitude towards quality or any other type of possitive change they consider "allien or strange", the internal audits would have a very helpful "double role" function: One >> Being a very professional auditor during the audit and, of course, avoiding the role of consultant during the audit, but afterwords s/he will be a "change promoter" in his own department in order to push the closing of non conformances, taking care of going deep to find the root causes of problems and the application of preventive actions, convinced that is better to "wash the dirty cloth at home" before external visitors arrive. This second "personality" has been in my experience very very helpful in small/medium sized companies, making possible the establishment of a "quality gang" in most of the cases more effective than an "official" Quality Comitee, that also in most of the cases is only a corporative "show". The activities of quality gang after the internal audits do not brake any "judge and jury" or any other rule.


barb butrym

Quite Involved in Discussions
All in all there is no rule...just opinions, and i believe probably as many opinions as there are people...

I will be addressing a convention in November on this issue including contract-vs-inhouse all falls under the same umbrella...anyway, the attendance is expected to be at max....or close to it..WHY do you think that is?
Its a very difficult call, and all you can do to address it, is trial and error...what works for you, your company and the audit team this moment in time...????

Far too many factors to give a rule ...

BTW..the session is on what to consider and how to make that decision.....anyone got some comments to add to that?

[This message has been edited by barb butrym (edited 12 March 2000).]
Really impressive thread. and that too 22 years ago!!!!
My opinion as auditor/trainer is always have at least 3 persons. 1 person has an issue who will audit thee, while two persons will save each other during internal audits like rivalry/NCs Competition. 3rd person will act to balance things up. Internal Audit is about team size dynamics too.

In companies like too low employees like 2-3, internal auditing can also be outsourced to some independent expert/party. Here in Pakistan, I have seen companies use this rule, even large complex organizations do so, to have more independent and expert insights on their systems

Rest it is true, that no single rule employs to all, we can just advise/train on best practice as target is - Effective Audit that adds value.

John Broomfield

Super Moderator
Each internal auditor should audit frequently enough to maintain their competence.

So, at least one audit per quarter?

Get this rule right and you may avoid an embarrassment of volunteers!
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