Architecture firms almost always bring in outside consultants for structural, mechanical, electrical, civil, and landscape work. How you handle those costs in your books depends on how your contracts are written, and getting this wrong distorts your revenue, your margins, and your understanding of how profitable the firm actually is.

There are three common approaches, and each one works differently on your financial statements.

Pass-through at cost means you pay the consultant and bill your client the exact same amount. The client reimburses you dollar for dollar. In your books, the reimbursement should not count as revenue in the traditional sense. Many firms set up a separate reimbursable income account and a matching reimbursable expense account so the two offset each other. This keeps your revenue figures clean and your profit margins reflect only the work your firm actually performed. If you lump reimbursables into regular revenue, your top line looks inflated but your margin percentage drops, which makes it harder to benchmark your firm’s performance.

Marking up consultant fees is where the firm adds a percentage on top of what the consultant charges. A 10% or 15% markup is common. The full amount billed to the client is revenue. The consultant’s invoice is a cost of services. The spread between what you pay and what you bill is real gross profit. This is straightforward to record, but you need to track it at the project level so you can see how much of your project revenue is markup versus your own design fees. Without that visibility you might think a project was highly profitable when most of the “profit” was just consultant markup that carried its own administrative cost to manage.

Absorbing consultant costs in your fee means your proposal to the client is one number that covers everything, your design work and all consultant fees. The client doesn’t see the breakdown. You pay the consultants out of your overall fee. This is the riskiest approach because if the structural engineer’s scope grows or the landscape consultant needs extra revisions, those costs come directly out of your margin. In your books, consultant payments are a direct project cost that reduces profitability. You need to budget consultant costs carefully during the proposal stage and track actuals against that budget throughout the project.

Regardless of which method you use, track consultant costs at the project level. Every invoice from every consultant should be coded to the specific project it belongs to. If you have projects using different contract structures, your chart of accounts needs to handle all three approaches without mixing them together. This is where a lot of professional services firms get tripped up. They use one generic “subcontractor” expense account for everything and lose the ability to understand what’s really happening on each job.

Also pay attention to timing. You might pay a structural engineer in March but not bill the client for that reimbursable until April. If your books don’t account for that lag, your monthly financials will show a cost without the corresponding revenue, making one month look bad and the next look artificially good. Accrual-based tracking handles this better than cash-based for firms with significant consultant activity.

The right approach for your firm depends on your market, your client expectations, and how you want to position your fees. What matters from a bookkeeping standpoint is that the books match the contract. If you’re passing through at cost but recording it as regular revenue, or absorbing costs but not budgeting for them, your financial statements won’t tell you the truth about your firm’s health. Working with Rock Steady Bookkeeping or another bookkeeper who understands project-based businesses makes a real difference here because the setup decisions affect every report you pull going forward.