Internal fraud is difficult to detect, which is understandable given the wide variety of techniques that range from stealing cash and supplies, to falsifying expense reports and benefit claims, embezzling funds, and accepting kickbacks from vendors, contractors, and suppliers. But catching dishonest employees isn’t impossible if you focus on the task, take a strong stand against fraud and shake things up a bit.

Here are three relatively straightforward methods that can help your company detect internal fraud:

1. Scrutinize Expenses. When employees feel that expense claims aren’t stringently reviewed, they may pad their reports with inflated or nonexistent expenses. Depending on the employee’s rank, these padded expenses can mount up quickly.

Case in Point: The COO of a paper company routinely submitted monthly expense claims of more than $10,000. On the face of it, the charges all seemed legitimate.

But in reality the executive was claiming full-fare airline tickets to destinations unrelated to the company’s business. He would then refund the tickets to his credit card without reimbursing the company. In addition, he was claiming $3,000 a month in non-existent lodging and car-rental costs, and then using the money to build and maintain his wine collection. The deceptions weren’t discovered until a routine audit, which found that those responsible for overseeing expense accounts were careless.

Expense account fraud represents a greater threat because employees become comfortable with it and move on to submitting claims for even higher expenses or switching to more complex and damaging fraud schemes. Be certain that those who check expense reports are rigorous in their reviews and that everyone from the top down at your business knows that expense claims will be scrutinized.

2. Shake Up Routines. Fraudsters tend to develop habits based on a company’s regular schedules. For example, they know when monthly audits are due and take steps to suspend the fraud and hide evidence until the audits are complete.

Case in Point: A company’s warehouse manager was taking kickbacks from vendors in return for preferential treatment during contract bids. One day, the auditors turned up for an unannounced inventory count. When they arrived, the manager was sharing a bottle of scotch with one of the vendors and the kickback payment was in plain view on his desk.

If an out-of-sequence audit uncovers fraud at your company, be sure to publicize it. And be certain that everyone in the organization knows that unexpected reviews should regularly be expected.

3. Periodically Review Controls. Even if audits are conducted on a routine basis, you should still occasionally review the mechanisms aimed at deterring fraud. Criminally inclined employees spend time and effort learning how to circumvent controls. When they are successful, the company managers may think the controls are doing their job when, in fact, the business may be losing thousands of dollars.

Case in Point: A senior bank teller and her manager regularly stole large sums from the vault of a small community bank branch where they worked. Each month, just before the scheduled branch audit, the teller would replace the missing cash with bundles of blank paper. Her manager would “count” the cash and certify that the amount was correct.

After some cuts in the audit department, the bank trimmed the number of audits and required the auditor to make the actual count. But to save time and meet audit quotas, the auditor would count the stacks rather than the individual notes. The fraud remained undetected and wasn’t discovered until the manager was fired. Had the auditing process been reviewed, the company would likely have noticed the flaws in the controls and discovered the fraud much sooner.

The “perception of detection” is a crucial element in fighting fraud. You can help deter fraud with methods that heighten employees’ concerns about being caught. Consult a professional for advice about systems and controls that will work effectively at your organization, and consider setting up an anonymous hotline for reporting suspected fraud.