CEOs fret, understandably, over T&E expenses. Like cats at home, they picture the mice that are away splurging on imported brie and raiding the mini-bars. A whole industry exists to set and monitor travel spending, reining in the extravagance of executives, salespeople, and others who pay in advance for a full tank of gas even though they're driving only 20 miles and are on a first-name basis with both Smith and Wollensky.

But there exists another category of business traveler that, while less injurious to the bottom line, is also worth discouraging. These are employees who make reimbursement claims ridiculously late or not at all. Motivated by laziness, fear, or embarrassment, they may disrupt systems or end up shouldering a significant part of the costs themselves. That second behavior is good for profits but can be bad for morale.

The subgroup motivated by laziness postpones filing T&E forms for months or even years because, frankly, they can afford to. They are busy and disdain what they consider organizational "housework." Of course, when they do get around to filing that claim from 2004 they cause havoc in the accounting department.

The subgroup motivated by fear is more sympathetic. These are chiefly junior employees who are terrified of incurring their employer's displeasure with the least hint of profligacy. Faulting themselves when they can't find street parking, they don't report the $40 garage fee. Tips come out of their own pockets. They approach eating more like college students than members of the work force. A manager recently told me that young employees at her former company submitted receipts for Happy Meals.

The subgroup motivated by embarrassment is not so much sympathetic as pathetic. These are people who, faced with the itemized receipts issued by so many restaurants, can't bear their supervisors or accounting departments knowing what slop they ingested while dining alone. The corned beef hash and Pepsi (NYSE:PEP) breakfast, two glasses of wine at lunch, and did I really eat a hot turkey sandwich and a piece of coconut cream pie at the same meal? And so they claim the least humiliating repasts (not expensing meals at all might raise questions) and swallow the balance.

It behooves companies to make post-trip reporting less onerous. One possibility is to take a page from government's playbook and go the per diem route. Government agencies give traveling workers a set amount to spend each day, determined by their destinations. Per diem systems--which are also used by some businesses--eliminate much unpredictability from T&E budgeting, simplify paperwork (receipts generally aren't required), and free travelers to maximize their own enjoyment within well-understood boundaries. And since employees pocket what they don't spend, per diem systems teach lessons about the value of thrift that may carry over into decisions made back at the office.

Whatever system you use, encourage employees to practice moderation on the road. Limousines and Chateau Latour will be frowned upon. But please don't try to represent the business fueled by a quartet of McNuggets.

Leigh Buchanan is an Inc. editor-at-large. She can be reached at