Written instruction and waiver in the United States

The work is built, someone on the owner's side told you to build it, and nobody signed a change order. Does the claim survive?

In the United States the first answer is it depends on who the owner is. On private work a written-change-order requirement is an ordinary contract term, and the party it protects can give it up by conduct. On state and local public work the rule inverts. On federal work only the Contracting Officer binds the government.

The reason for the inversion is the point general treatments miss. It is not that public contracts are more formal. It is that a public officer who lacks authority to contract cannot be given it by the contractor's reliance. Waiver and estoppel act on the conduct of a party that could have agreed; they do nothing for one that never had the power to agree.

State law varies, and this page does not survey it. It states the rule only where it has read the authority — California, Ohio and Arizona on the public side, California on the private side, plus two decisions (Tenth Circuit, Wyoming) in which waiver was analysed against public-body owners, and the Federal Circuit on federal work. Fifty-state lists on this question circulate widely and are where over-claims hide. Check your own state.

Three answers to one question

(The table states the record found in the holdings below; the last column is opinion drawn from them.)

Private work: the requirement is a promise, and promises can be waived

The orthodox American position is that parties who wrote a contract can unwrite it, including a clause saying changes must be in writing. California's pattern jury instruction states the doctrine in the form a jury hears it: CACI No. 4522, Waiver of Written Approval or Notice Requirements for Changed or Additional Work (new December 2010, revised June 2011), requires the contractor to prove the owner "freely and knowingly gave up" its right to insist on compliance, and that "a waiver may be oral or written or may arise from conduct that shows [the owner] clearly gave up that right." Its authorities include Healy v Brewster: a requirement that extra work be approved in writing "may be altered or waived by an executed oral modification."

Two elements decide private-work claims. The standard of proof is high: the Directions for Use state that "the general rule of contract law is that waiver must be proved by clear and convincing evidence," citing City of Ukiah v Fones, while noting that some construction cases have not mentioned it. And conduct must point one way: an owner that tolerated one informal change has not "clearly" given anything up.

Pattern versus incident

Transpower Constructors v Grand River Dam Authority, applying Oklahoma law, found the contract's claim procedures waived. The contractor proved "several instances where GRDA, upon Benham's recommendation, paid Transpower for additional work even though Transpower had not complied with" them. The contract's anti-waiver clause did not save the owner: "it would be manifestly unjust for us to enforce this provision after GRDA, through its own course of conduct, has essentially waived the benefits of the provision's protection." An anti-waiver clause can itself be waived by a course of non-enforcement.

Rissler & McMurry Co v Sheridan Area Water Supply Joint Powers Board went the other way: "written field orders were regularly issued which were eventually incorporated into change orders." The formality had been observed, so a departure proved nothing. (Inference: neither court states the pattern-versus-incident line in those words; it is what the two outcomes jointly imply.)

★ What Transpower complicates. The defendant was, in the caption, "an Oklahoma Public Corporation," and the opinion does not discuss whether that mattered. So the public/private line on this page is not a uniform national rule: in at least one reported decision a public corporation's own course of payment waived its claim procedures. The same is true of Rissler: the owner was a joint powers board, and the Wyoming court analysed waiver on the evidence without suggesting it was unavailable against a public body.

Public state work: the rule inverts, and the reason is authority

On public work the question stops being did the owner waive the formality? and becomes did anyone with power to contract agree to pay for this?

California: the jury instruction draws the line itself

The Directions for Use to CACI No. 4522 say that the waiver instruction "is almost certainly limited to private contract disputes," citing P&D Consultants, Inc v City of Carlsbad. There a consultant sought payment for extra work on a municipal golf-course project, said to have been authorised orally by the City's project manager. The court held: "Unlike private contracts, public contracts requiring written change orders cannot be modified orally or through the parties' conduct." It adopted the reason given in Katsura v City of San Buenaventura: "Persons dealing with a public agency are presumed to know the law with respect to any agency's authority to contract." And it closed restitution: a private party cannot sue a public entity "on an implied-in-law or quasi-contract theory, because such a theory is based on quantum meruit or restitution considerations which are outweighed by the need to protect and limit a public entity's contractual obligations."

Two precision points, because this is where summaries overstate California. Estoppel was not decided: the opinion records that estoppel, waiver and ratification had not been raised at trial. And the older contrary authority no longer carries weight: Weeshoff Construction Co v Los Angeles County Flood Control District, which CACI No. 4522 cites with "cf.," for the proposition that a public agency may waive written change-order requirements. P&D, quoting Katsura, says that Weeshoff's "continuing viability" is "questionable" and that it "is contrary to the great weight of authority." The later cases control.

California private work also carries a statutory change-order claim procedure from 1 January 2026, treated on its own page: California SB 440.

Ohio: an agent cannot waive, and the owner's waiver needs clear proof

Foster Wheeler Enviresponse, Inc v Franklin County Convention Facilities Authority concerned contaminated-soil removal far beyond the base quantity. The Supreme Court of Ohio applied a rule from Baltimore & Ohio RR Co v Jolly Bros & Co (1904), 71 Ohio St. 92:

"In the absence of express authority, an engineer, architect, superintendent or inspector in charge of or assigned to public building or construction work has no power to waive or modify a stipulation requiring a written order for alterations, even where that person may authorize alterations in writing."

The construction manager's authority was "limited to ordering minor changes in the Work not involving an adjustment in the Contract sum or an extension of the Contract Time" — the same shape as the A201 minor-change power below. A power to order changes that cost nothing is not a power to agree changes that cost something.

But Ohio is not an absolute bar. The stipulation is "for the benefit of the employer," so "proof of a waiver must either be in writing, or by such clear and convincing evidence as to leave no reasonable doubt about it." The owner knew quantities were rising and did not object — "However, mere knowledge, and even acquiescence, is not enough for recovery." The public owner itself can waive; its agents cannot, and knowledge plus silence is not proof.

Arizona: actual authority, and a split inside one state

Kaman Aerospace Corp v Arizona Board of Regents. ★ The spelling is Kaman; "Kamen," which circulates, is wrong.

The contract was for an optical test instrument for the University of Arizona, not a building — an authority-to-contract decision that transfers to construction, not a construction decision. The design guidelines were revised repeatedly and the contractor claimed the revisions as changes; modifications required "both parties' written agreement." A jury found for the contractor; the Court of Appeals reversed: "until an ABOR officer with contracting authority executed a document embodying both the change and its cost, ABOR was not bound." The engineers who directed the revisions were not among the officers designated to execute contracts, and the parties' course of performance could not substitute for an authorised official.

Kaman expressly did not decide whether later conduct ratified the engineers' directions, or whether the rule differs where a public body acts in a proprietary capacity — neither was argued. Those arguments remain open. And the contrast inside Arizona is sharp: private-work law there has recognised waiver of written-authorisation clauses since Sitkin v Smith.

Why the rule inverts

(Inference, from the decisions above and the federal authority below.) In each case the court asked who had power to bind the public body before asking what the parties did. Public entities contract through officers whose authority is fixed by statute, charter, regulation or board policy, and the contractor is charged with knowing those limits. Where the person who directed the work had no power to agree, their conduct waives nothing, and the contractor's reliance cannot supply the missing power. That is why the private-work cases do not transfer.

The word "jurisdictional"

Practitioners often call the public-work writing requirement "jurisdictional" in particular states. NEGATIVE FINDING The word does not appear in P&D Consultants, Foster Wheeler or Kaman, each checked for it on 22 September 2026. What those decisions establish is that the requirement goes to authority. Other states commonly added to the "jurisdictional" list were not verified and are not named here.

Federal work: only the Contracting Officer — and what supplies the rest

The foundation is Federal Crop Insurance Corp v Merrill: "anyone entering into an arrangement with the Government takes the risk of having accurately ascertained that he who purports to act for the Government stays within the bounds of his authority." The appropriations side is Office of Personnel Management v Richmond: payment from the Treasury must be authorised by statute, and an employee's erroneous advice cannot estop the government. FAR 43.102(a) applies the rule to modifications: "Only contracting officers acting within the scope of their authority are empowered to execute contract modifications on behalf of the Government." Other personnel shall not "direct or encourage the contractor to perform work that should be the subject of a contract modification."

Winter v Cath-dr/Balti — what it actually held

Winter v Cath-dr/Balti Joint Venture, on appeal from the Armed Services Board of Contract Appeals, is usually summarised as "rejecting an implied-authority theory." That is true and incomplete. It decided three things.

Apparent authority does not bind the government. "Where a party contracts with the government, apparent authority of the government's agent to modify the contract is not sufficient; an agent must have actual authority to bind the government."

Implied actual authority exists, but not where the contract withholds it. The Board had found the Navy's project manager authorised to direct changes. The Federal Circuit accepted that "[a]uthority to bind the government may be implied when it is an integral part of the duties assigned to the particular government employee," and held it inapplicable: "Modifying the contract could not be 'considered to be an integral part of [the ROICC project manager's] duties' when the contract explicitly and exclusively assigns this duty to the CO." The contract had told the contractor that where anyone other than the Contracting Officer directs a change, "it is the Contractor's responsibility to make inquiry of the Contracting Officer before making the deviation."

Ratification remained open. "Ratification requires knowledge of material facts involving the unauthorized act and approval of the activity by one with authority." The CO's own final decision had found entitlement on several claims; whether that was ratification turned on the CO's knowledge, a question of fact the Board had not addressed, so those claims were remanded. One claim was affirmed on the Board's Differing Site Conditions finding, which the Navy did not challenge on appeal.

(Opinion.) On a federal construction contract carrying an exclusive-authority clause, implied actual authority will rarely rescue a direction from a project manager, inspector or Contracting Officer's Representative. Ratification and the contract's own clauses are where recovery is found.

What supplies the rest

1. Ratification. At case law, knowledge plus approval by one with authority (Winter). Administratively, FAR 1.602-3 lets the head of the contracting activity ratify an "unauthorized commitment" — one not binding "solely because the Government representative who made it lacked the authority" — subject to conditions including that the government received a benefit, the contract would have been proper if made by a contracting officer, the price is fair and reasonable, and funds were available.
2. The Changes clause's own gateway. FAR 52.243-4(b) (JUN 2007) treats "any other written or oral order (which, as used in this paragraph (b), includes direction, instruction, interpretation, or determination) from the Contracting Officer that causes a change" as a change order, provided the contractor gives written notice stating "(1) The date, circumstances, and source of the order; and (2) That the Contractor regards the order as a change order." Paragraph (c) makes the clause exclusive. The gateway runs through the Contracting Officer; it holds the CO to directions the CO gave or adopted, and does not bypass the authority rule. The doctrine is on constructive change in the United States; the 20-day cost look-back in paragraph (d) is on the US change-order hub.
3. Clauses that do not depend on who gave the order — (Inference) differing site conditions, for example, which is the clause under which Winter's one affirmed claim sat.

What is not available: a claim on a contract implied in law. Tucker Act jurisdiction "extends only to contracts either express or implied in fact, and not to claims on contracts implied in law" — Hercules Inc v United States.

Edition note. Quote the clause as incorporated in your contract. The text above is FAR 52.243-4 (JUN 2007) as displayed at FAC 2026-01. Under the Revolutionary FAR Overhaul, agencies administer Part 43 under class deviations, agency by agency. The preamble of the proposed rule for Parts 14, 28, 36 and 52 published 18 September 2026 (FAR Case 2026-010) does not mention 52.243-4 (its amendatory text was not read in full), and no Part 43 proposed rule had issued as at 22 September 2026. FAR 1.602-3 falls within the 23 June 2026 proposed rule for Parts 1, 2, 4, 33 and others; quote it as in force at the relevant date.

The AIA layer: who can sign what under A201–2017

On a private project using AIA A201–2017, the form answers the authority question before any waiver argument begins — and the person most likely to be directing work cannot change the price.

• §2.1.1 — the Owner "shall designate in writing a representative who shall have express authority to bind the Owner with respect to all matters requiring the Owner's approval or authorization." That person's conduct is the conduct that counts.
• §4.2.8 — "The Architect will prepare Change Orders and Construction Change Directives, and may order minor changes in the Work as provided in Section 7.4." Prepare, not issue.
• §7.2 Change Order — signed by Owner, Contractor and Architect.
• §7.3 Construction Change Directive — signed by Owner and Architect (§7.3.1); it "requires agreement by the Owner and Architect and may or may not be agreed to by the Contractor" (§7.1.2), and on receipt the Contractor "shall promptly proceed with the change in the Work" (§7.3.6).
• §7.4 Minor changes — the Architect alone, only for changes consistent with the intent of the Contract Documents that adjust neither Contract Sum nor Contract Time.

★ §7.4 carries a waiver that runs against the contractor, added in 2017. "If the Contractor believes that the proposed minor change in the Work will affect the Contract Sum or Contract Time, the Contractor shall notify the Architect and shall not proceed to implement the change in the Work. If the Contractor performs the Work set forth in the Architect's order for a minor change without prior notice to the Architect that such change will affect the Contract Sum or Contract Time, the Contractor waives any adjustment to the Contract Sum or extension of the Contract Time."

Read §4.2.8 and §7.4 with Foster Wheeler and the structure is plain. The Architect's unilateral power is a power over changes that cost nothing. A priced direction from the Architect is either a Construction Change Directive the Owner has signed, or no instrument at all — and the contractor is then arguing waiver by the Owner's conduct. The Architect's comfort is not the Owner's waiver.

Edition traps. The Architect's determination is §7.3.4 in 2017 (§7.3.7 in 2007); the duty to proceed on a CCD is §7.3.6 (§7.3.5 in 2007). The AIA 2024 Design-Build family does not incorporate A201; A141–2024 carries its own general conditions. And a contractor that has lost the instruction argument usually faces a notice argument next: Article 15's Claim machinery is on the US change-order hub.

The strongest case against this page's framing

A careful opponent would say the public/private flip is overdrawn. Transpower found waiver against a public corporation; Rissler analysed waiver against a joint powers board on the evidence; Weeshoff is cited for the proposition that a California public agency may waive; Foster Wheeler contemplates a public owner's waiver on sufficient proof. All true. But Transpower and Foster Wheeler each turn on conduct by the owner itself or someone with authority — never on a subordinate's direction plus the contractor's reliance — and Weeshoff, whose continuing viability P&D calls "questionable," was not independently read for this page. (Opinion.) The flip is not "public owners can never waive." It is that on public work only the principal's own conduct counts, and it must be proved to a standard the everyday site record rarely meets.

UNVERIFIED Substantial compliance and actual-knowledge / no-prejudice arguments against a public writing requirement were not researched for this page; no authority is stated for them.

A comparison, clearly labelled

This section compares regimes. Nothing in it is authority for a US proposition.

Canada has no equivalent flip. Its leading case on waiver of a written-authorisation requirement, Colautti Construction Ltd v City of Ottawa (1984), was decided against a municipality, and the City's status did not immunise it. The Canadian answer rests largely on that one decision; the American answer rests on a body of authority-to-contract doctrine that asks, first, whether the person who gave the direction could bind the owner.

What to do about it

(Opinion, offered as working practice rather than as authority.)

1. Classify the owner first — private, state or local public, or federal.
2. Name the person with authority on day one. Under A201–2017, the §2.1.1 representative; on federal work, the Contracting Officer, not the COR or project manager. Route every priced direction to that person in writing.
3. On private work, build the pattern if you mean to rely on it: informal changes invoiced and paid, at Owner level, documented.
4. On public work, do not plan on waiver. Get the authorised signature first, or a written adoption by the authorised officer afterwards — and if one exists, argue ratification.
5. On federal work, serve the 52.243-4(b) notice with both elements on the Contracting Officer the moment a direction looks like a change.
6. Under A201–2017, never proceed on a "minor change" you think costs money. Notify and stop.

Where the change was never directed at all, see constructive change in the United States. Where a change order was signed and the claim died inside it, see change order releases in the United States. Where the direction exceeded the changes power altogether, see cardinal change.

About this material Library content is general information about construction claim practice, not legal advice. Entitlement, deadlines and procedure are governed by your own contract and by the law of the place the work is performed. Reviewed September 22, 2026 · Report a correction