What Should an Architecture Firm’s Invoice Show to Get Paid Without Questions?

Percentage-of-construction fees: the arithmetic, month to month

When the fee is a percentage of construction cost, B101–2017 Section 11.1 sets it as a percentage “of the Owner’s budget for the Cost of the Work, as calculated in accordance with Section 11.6.” Section 11.5 splits the fee across five phases, Schematic Design, Design Development, Construction Documents, Procurement and Construction, with blanks the parties fill in that add up to 100 percent. The form does not supply the phase percentages; the signed agreement does.

Section 11.6 gives the progress-payment rule. Progress payments for each phase are calculated “by multiplying the percentages identified in this Article by the Owner’s most recent budget for the Cost of the Work,” and “Compensation paid in previous progress payments shall not be adjusted based on subsequent updates to the Owner’s budget for the Cost of the Work.” Section 11.6.1 adds that when parts of the project are deleted or not built, the architect is paid for those parts to the extent services were performed on them, and is entitled to compensation for all services performed whether or not the construction phase starts.

So the invoice has to say which budget it used. Illustrative example: a hypothetical agreement sets the fee at 8 percent of the owner’s budget, with 15 percent of the fee assigned to Schematic Design and 20 percent to Design Development. On a $5,000,000 budget the total fee is $400,000, and Schematic Design is worth $60,000; it is billed over two months and finished. Before Design Development starts, the owner raises the budget to $5,500,000. The total fee becomes $440,000 and Design Development is worth $88,000. At 40 percent complete, earned to date is $35,200, nothing was billed before, and $35,200 is due this period. The $60,000 already billed for Schematic Design stays as it was. Every percentage and dollar figure here is invented; the agreement sets the real ones.

Two answers belong in writing before the first invoice. First, what happens when the budget changes in the middle of a phase. The form says past payments are not adjusted; how the unfinished part of the current phase is recomputed is worth agreeing with the client in writing, then applying the same way every month. Second, how the construction phase is measured. “In proportion to services performed” can be read from the months of construction elapsed against the schedule, from the contractor’s approved pay applications, or from the firm’s own hours against its budget for the phase. Pick one, name it on the invoice, and keep it for the life of the project.

Print the budget figure and its date on every invoice of a percentage fee. When the client’s finance team asks why this month’s Design Development line is larger than last month’s plan, the answer is on the page.

Additional services and reimbursables: their own lines, their own paper

Additional services do not belong inside a phase’s percent complete. Bill each one on its own line, with the amendment or written authorization that created it, its own fee or hourly basis and its own earned-to-date column. Hours for an unauthorized extra that land inside a phase make the phase look further along than the drawings show, and that is exactly the line a client questions. Getting the authorization in writing before the work is a separate problem, covered in the guide to additional services without an amendment.

Reimbursable expenses, under Section 11.8.1 of B101–2017, are in addition to the fee and include expenses “directly related to the Project.” The standard list includes transportation and authorized out-of-town travel and subsistence; printing, reproductions and plots; postage, handling and delivery; permitting and other fees required by the authorities having jurisdiction; renderings, models and presentation materials requested by the owner or required for the project; overtime at higher than regular rates, if authorized in advance; site office expenses; and other similar project-related expenditures. On the invoice, group them by those categories, total each one, and keep the receipts in the same order. Section 11.10.2.3 makes records of reimbursable expenses, of supplemental and additional services and of hourly services “available to the Owner at mutually convenient times,” so every line should be one the firm can back with a receipt the day it is asked.

Can reimbursables carry a markup? Only if the agreement says so. Section 11.8.2 of the standard form bills reimbursables at the expenses incurred by the architect and its consultants “plus” a percentage the parties fill in, which can be zero. Owners edit that line. The University of Wisconsin System’s owner-issued copy of B101–2017 deletes Section 11.8.2, says “All reimbursables must be authorized in advance by the Owner,” caps out-of-town travel at the State of Wisconsin’s reimbursement rates, and adds that listing reimbursables or additional services in an accepted proposal “shall not be construed as authorization to proceed.” The same reading applies to consultants’ invoices passed through to the client, and the guide to consultant invoices and markup covers that count.

A markup the agreement does not state, or a reimbursable the client never authorized where the contract requires it, is not a negotiating point. It is an error the client can find in records it is entitled to see, and it can hold the whole invoice while one line is argued.

What backup a public client requires with each invoice

On public work, the contract defines a proper invoice, and an invoice that is not proper may not start the payment clock at all. Read the invoicing section of each public contract on the first day and turn it into a one-page sheet for that client before anyone prepares the first billing.

Federal fixed-price architect-engineer contracts carry two payment clauses worth reading together. FAR 52.232-10 says estimates of “the amount and value of the work and services performed” are made monthly, and that the estimates, “along with any supporting data required by the Contracting Officer,” are prepared by the contractor and submitted with its voucher. The contracting officer may withhold up to 10 percent of the amounts due “only if” it determines that a withholding is necessary to protect the government’s interest, and releases the excess once the work is substantially complete. Before final payment, the contractor signs a release of claims, except those it lists. Under FAR 52.232-26, progress payments are due on the 30th day after the government approves the contractor’s estimates, an invoice that is not proper is returned within 7 days with the reasons, and an interest penalty on a late proper invoice is paid automatically, without a request, when the clause’s conditions are met. The FAR is being rewritten under the Revolutionary FAR Overhaul; the text quoted here is both clauses as published on acquisition.gov on October 22, 2026 (FAC 2026-01, effective March 13, 2026), and the version that binds a firm is the one in its contract.

States write their own rules. Florida’s Local Government Prompt Payment Act defines a proper invoice as one that conforms with all statutory requirements and all requirements the local government specifies, and says those requirements “must be included in the contract.” For purchases other than construction services, the clock runs from the date a proper invoice reaches the chief disbursement officer, after approval by the governing body if one is required. Payment is due 45 days after that date, and a payment still unpaid 30 days after its due date bears interest at 1 percent a month, which the vendor has to invoice to receive. If an invoice is improper, the local government must say so in writing within 10 days of receiving it and indicate the corrective action needed. In Texas, the prompt payment chapter’s payment deadlines do not apply to a payment when the invoice is not mailed to the person it is addressed to “in strict accordance with any instruction on the purchase order relating to the payment.”

Owners also write backup into their own agreements. The Wisconsin copy of B101–2017 requires every request for payment to come with a document showing the project’s progress to date. Which statute reaches a given design contract, including whether design work counts as construction services under Florida’s act, is a question for the firm’s attorney; this is a plain reading of the text, not legal advice. The operating point does not change: the backup list lives in the contract, and the person who sends invoices needs it before the first one goes out.

• Where the invoice goes: the portal, billing address or mailbox named in the contract or purchase order, and the person it is addressed to.
• The numbers the contract requires it to carry: contract, task order, purchase order and line item, or the client’s own project number.
• What travels with it: the monthly estimate, the progress documentation, receipts for reimbursables, consultant invoices, and any form the contract names.
• Who approves it on the client side, and the date their window to object closes.
• Whether the client withholds a share of each payment, and what releases it.

Why clients question an invoice

The questions that hold a payment can be sorted, and each sort has an office fix:

• A percent complete ahead of what the client has seen. For example, the invoice says Construction Documents is 60 percent complete; the client has seen nothing since Design Development. Fix: the one-line note on each phase row, and a progress set or a short narrative attached when the contract or the client asks for one.
• An extra with no paper. An additional service billed with no amendment or authorization number behind it. Fix: no additional-service line goes out without its document number.
• Reimbursables without receipts or approval. A travel line on a contract that requires advance authorization, or a markup the agreement does not allow. Fix: bill reimbursables from the receipts, with the authorization reference where the contract requires one.
• The wrong base on a percentage fee. The invoice uses an old construction budget, or a phase percentage that does not match the agreement. Fix: the budget and its date printed on every invoice.
• Missing numbers or the wrong address. No purchase order number, no task order, or sent to the project manager instead of the billing office. Fix: the one-page client sheet above.
• Arithmetic that does not tie. This period does not equal earned to date minus previously billed, or previously billed does not match the client’s own payment records. Fix: a second person ties the totals before the invoice is released.

One kind of hold is different. Section 11.10.2.2 of B101–2017 says the owner shall not withhold amounts from the architect’s compensation to impose a penalty or liquidated damages, or to offset sums requested by or paid to contractors for the cost of changes in the work, unless the architect agrees or has been found liable in a binding dispute resolution proceeding. A hold of that kind goes to the principal and the firm’s attorney, not back into the billing queue.

Track every hold: one log, read every Friday

A held invoice is easy to lose because nothing happens: no payment, no rejection, just a quiet client. The fix is a hold log kept by whoever sends invoices, with one row each time a client questions, returns, short-pays or sits on an invoice.

The client’s window to object matters because it puts a date on silence. On federal fixed-price A-E work, an improper invoice is returned within 7 days. Florida’s local governments have 10 days to name an improper invoice in writing. Texas Government Code section 2251.042 requires a governmental entity to notify a vendor of an error or disputed amount no later than the 21st day after it receives the invoice, with a detailed statement of the amount disputed, and lets it withhold no more than 110 percent of the disputed amount. If the dispute is resolved in the entity’s favor, the vendor submits a corrected invoice. Private agreements may set a window of their own, or none.

• Client, project, invoice number and date, the date it was sent, and the proof: portal confirmation, email or tracking number.
• Amount billed, amount held, and the line or lines in question.
• The reason, sorted into the list above, and the client’s own words.
• The window to object, where a contract or statute sets one, and the date the client’s notice arrived.
• Who at the firm owns the fix, the date the corrected invoice or backup went out, and the date paid.

Read the log every Friday, in ten minutes, with the project managers whose invoices are on it. Two numbers go to the principal: the dollars on hold and the age of the oldest hold. Any hold older than one billing cycle gets a call from the principal, not another email. Illustrative example: a hypothetical firm sends 30 invoices a month, and over a quarter 11 are held. Five lack a purchase order number, three show a percent complete the client disputes, two carry reimbursables with no receipts, and one is an owner offsetting a contractor’s change order. Ten are office fixes; the eleventh goes to the attorney. The numbers are invented; the firm’s own log gives the real ones.

When not to hire anyone for this

If the firm bills a handful of projects, the layout above, a one-page sheet per public client and the hold log are an afternoon of setup and ten minutes a week. The firm’s project-accounting software may already print the phase table; the work is in what goes into it. No outside help is needed.

Call the firm’s attorney rather than a consultant when a client is withholding to offset a contractor’s costs, when a public client has let its window pass and still will not pay, or when a notice to stop work is on the table. We give no legal advice and read no agreement for its legal effect.

An outside count is worth paying for when invoice holds are one leak among several between the signed agreement and the cleared payment: phases finished but billed a month late, additional services drawn on a verbal yes, consultant invoices passed through after the billing day, interest never billed. That is the work of an architecture & engineering business consultant who reads records rather than drawings. The Revenue Review reads it under the Delivery → Invoice hand-off, from read-only exports of agreements, amendments, time by phase, invoices, the hold log if there is one, and the aging. It ends in a written report the firm keeps, with a monthly dollar figure wherever the records support one, a ranked list of fixes and a 90-day plan. It does not contact clients, rewrite agreements or give legal advice. It takes two weeks. We are not architects or engineers, and there is no published A/E client case study on this site yet.

If it is unclear whether that is worth a fee, the next step is a free 20-minute call, where a firm whose holds are small and rare is told so.