I agree with previous comments about internal audits and would like to sum up and expand the pros and cons for this type of audits.
PROS
1. It helps compare your practices and processes against proposed prodecures and make corrections
2. It reduces the risks/chances of frauds
3. It ensures that accounting staff keep records up to date and are vigilant
CONS:
1. I don’t agree with @gh56 about the cons for internal audits. Any type of actions/audits can fall to planned fraud, not just internal audits. But I agree that internal audits are not full proof that it can catch all the frauds.
2. Internal audit are mostly hired from outside of the company, therefore, they may not work for the betterment of the company, but just for profit.
3. Internal audits mean additional costs for the company.