Chances are you’ve got an employee spending problem, and your company could lose as much as $26,000 this year to expense reporting mistakes or just plain fraud. That’s according to these guys.

Most mistakes aren’t malicious. Honest errors, wrong receipts and typos could be to blame. Check out four common expense reporting mistakes and spending policy violations, and learn how to help employees avoid them.

1. Overspending

Employee spending should be predictable. But budgets get blown fast when overspending gets out of control. Most companies have established spending limits. Few, however, do a great job communicating spending policies to their employees.

Three tips for curbing overspenders:

Access and internal communications. Put your spending policy on the internal editorial calendar. Communicate policy updates and reminders, even spending tips and FAQs, to your employees on a regular basis. Put your spending policy in a place where employees can easily find and access it whenever they need a reference.

Informed approvers. Spenders make mistakes. That’s why we have tiered-approval processes, right? Be certain your managers understand company spending policies and understand how to enforce them during the approval process. If you’re not already using automatic expense reporting to flag policy violations, give approvers an easy-to-use cheat sheet with limits and requirements they’ll need to enforce policy.

Informed violations. Consider policy violations an educational opportunity. Equip approvers with standard policy language to use when a violation comes up in an expense report. Instead of simply rejecting a report, approvers should tell employees the violation and the proper policy. Modern, automatic expense reporting software can also inform employees of policy violations — even before expense reports are submitted for approval.

2. Duplicate charges

Duplicate expenses isn’t always double-dipping. Employees may accidentally auto-import transactions from a credit card that they’ve manually added, or uploaded the same receipt twice. If your approvers aren’t on the lookout for these violations, your expense management software should be. Be sure your software is smart enough to detect and flag transactions or receipts that seem similar.

3. Inaccurate input

Data entry into spreadsheets is the top culprit for inaccurate expenses. So, if you haven’t already, it might be time to step away from the spreadsheets. Expense management software uses imported credit card transactions to add expenses to a report and requires receipts to back them up. The IRS requires receipts for charges over $75; your company may require receipts for less. You can save time and accuracy in expense reporting by making the process automatic.

4. Padding

OK, here’s where mistakes get questionable. Simple rounding, inflated prices and seemingly negligible small expenses (i.e., “coffee with a client”) add up, fast. It’s fraud. While there’s no solid way to flag this behavior, educating your approvers about the padding pitfall helps. If an approver suspects an employee of padding, it’s important to involve HR and deliver consequences that deter future fraud.