Follow Your Own Rules: Cost Accounting Compliance and Why Consistency Is the Law

Published 2026 | TIKC NewsWire

Here is a rule that sounds obvious but trips up growing contractors: once you tell the government how you account for your costs, you have to actually account for them that way, consistently, on every contract. The world of Cost Accounting Standards can feel like something only big primes worry about, and full coverage often is. But the underlying principle reaches further than most owners think. Whether you are formally covered or just following your own established practices, drifting from how you said you do things, or booking the same kind of cost differently depending on which job can absorb it, can turn into a compliance problem.

Consistency is the whole idea

The heart of cost accounting compliance is consistency. You decide, and where required you disclose, how you treat costs: what goes into direct versus indirect, how you allocate overhead, how you handle a given expense. Once that is your practice, you have to apply it the same way across all your government work and across time. The government relies on that consistency to compare, audit, and trust your numbers. When you switch how you book a cost case by case, you break the thing the whole system depends on. Our overview of Cost Accounting Standards covers how this scales as you grow.

How honest firms drift

Few contractors set out to break their own accounting rules. It happens gradually as you grow. You treat a cost as indirect on one contract and direct on another because it helps that month. You quietly change how you allocate overhead without updating your disclosed practice. You let the bookkeeping follow convenience instead of policy. Each drift makes your incurred cost picture inconsistent, and inconsistency is exactly what auditors are trained to spot. What felt like small, practical choices reads, from the outside, like numbers you can move at will.

Why inconsistency looks like manipulation

The danger is not that one method is right and another is wrong. Often either treatment could be fine if you picked one and stuck to it. The danger is choosing differently depending on which choice pays you more on a given contract, because that looks like you are steering costs to maximize recovery. That is how a cost-accounting drift starts to resemble the cost-shifting and mischarging the government pursues, and why a sound, consistent accounting system is your protection. Pick your practices, write them down, and apply them the same way every time.

What to do now

• Write down your practices. Define how you treat direct, indirect, and overhead costs, clearly and in one place.
• Apply them consistently. Book the same kind of cost the same way on every contract and every month.
• Do not choose by convenience. Never pick a cost treatment because it pays more on a particular job.
• Update formally, not quietly. If you change a practice, change it openly and across the board, not in the shadows.
• Keep your system sound. Maintain an accounting system that actually enforces your stated practices.

Growing into bigger, more complex contracts is the goal, and your accounting has to grow up with you. The rule is simpler than it sounds: decide how you do things, and then actually do them that way, every time. Consistent, documented cost practices keep your numbers trustworthy and keep you clear of a problem that quietly builds as you scale. Brick by brick.

FAQ

What is the core of cost accounting compliance?

Consistency. Once you decide and, where required, disclose how you treat costs, you must apply that treatment the same way across all government work and over time.

Do small businesses have to care?

Full Cost Accounting Standards coverage often applies to larger contractors, but the principle of following your own established, consistent practices reaches smaller firms too.

Why is inconsistency the problem?

Either treatment may be acceptable if applied consistently. Choosing differently based on which pays more looks like steering costs to maximize recovery, close to mischarging.

How do I stay compliant?

Write down your cost practices, apply them consistently, never choose a treatment by convenience, change practices openly rather than quietly, and keep a sound accounting system.

Sources

Federal Acquisition Regulation. (2026). Part 30 and 48 CFR Chapter 99, Cost Accounting Standards, and 31.201-2 consistency requirements.

Defense Contract Audit Agency. (2026). Contract Audit Manual, cost accounting consistency and disclosed practices.

This article is general information, not legal advice.