Unilateral Modification
Also known as: Unilateral mod, CO-signed modification
What you do here: Perform the directed change, document your impacts, and pursue the equitable adjustment
At a Glance
- Who signs it
- The contracting officer alone — no contractor signature
- What it does
- Makes a change within the government's unilateral authority
- Governing authority
- FAR 43.103(b); the Changes clause and option clauses supply the authority
- Typical uses
- Administrative changes, change orders, exercising options, adding funds/incremental funding
- Your remedy
- Seek an equitable adjustment (then definitize by bilateral mod)
What It Is
A unilateral modification (FAR 43.103(b)) is a contract change the contracting officer signs alone, without the contractor's signature, because the government already has the authority to make it. That authority comes from somewhere specific — most often a contract clause. The four workhorse uses are: (1) administrative changes that don't affect the substantive rights of the parties (a new paying office, a corrected address); (2) change orders issued under the Changes clause (FAR 52.243-1 and its cousins), which direct a within-scope change; (3) exercising an option under an option clause; and (4) making changes authorized by other clauses, such as adding incremental funding. Because you don't sign it, a unilateral modification can direct you to do something you haven't agreed to price. That's not a trap by itself — it's how the Changes clause is supposed to work — but it shifts the burden to you: perform the directed change, document the cost and schedule impact carefully, and pursue an equitable adjustment, which the parties then usually definitize in a bilateral modification.
When You See It
- When the contracting officer issues a change order under the Changes clause directing a within-scope change.
- When the government exercises a priced option to extend the term or add quantity.
- When the contract needs an administrative change that doesn't affect the parties' substantive rights.
- When the government adds funds or incremental funding under the authority of a contract clause.
Key Features
| Feature | What It Means |
|---|---|
| One signature | Only the contracting officer signs — the modification takes effect on the government's authority, not your agreement. |
| Requires clause authority | The government can act unilaterally only where a clause (Changes, an option, funding) or the FAR authorizes it — not to rewrite the deal at will. |
| Change orders shift the money question | A unilateral change order directs the work now and leaves the price to be settled later via an equitable adjustment. |
| Administrative changes are neutral | A true administrative change (FAR 43.101) doesn't affect substantive rights — it can't quietly add scope or cut your price. |
| Followed by a bilateral mod | The equitable adjustment for a unilateral change order is normally finalized in a later bilateral (supplemental agreement) modification. |
The SDVOSB Angle
A unilateral change order is where a small SDVOSB can bleed cash: you're directed to do the work now and paid for it later, sometimes much later. Protect yourself with discipline, not resistance. Perform the directed change, but immediately give the contracting officer written notice of impact and start a cost file — segregate the changed-work labor, materials, and subcontract costs so your equitable adjustment is provable. If the modification is really an administrative change, confirm it doesn't touch your price or scope. And whenever an option is exercised or scope is added, re-run the limitations on subcontracting over the newly in-scope work.
How to Handle It
- Read the modification to confirm the authority it cites (Changes clause, option clause, funding) actually supports a unilateral action.
- If it's a change order, perform the directed work but promptly give written notice of the cost and time impact.
- Segregate and document the costs of the changed work so your equitable adjustment is provable.
- Confirm an "administrative change" truly doesn't affect price, scope, or your substantive rights.
- Push to definitize the equitable adjustment in a bilateral modification rather than carrying an un-priced change.
Watch Out For
- Treating a directed change as optional — ignoring a valid change order can itself be a default.
- Failing to give timely written notice of impact can weaken or waive your equitable adjustment.
- Not segregating changed-work costs makes the adjustment hard to prove and easy for the government to discount.
- Accepting an "administrative change" that quietly shifts scope or price without an equitable adjustment.
Run the Numbers
Frequently Asked
What is a unilateral contract modification?
A unilateral modification (FAR 43.103(b)) is a change signed only by the contracting officer, used where the government already has authority to act — administrative changes, change orders under the Changes clause, exercising an option, or adding funds. The contractor does not sign it. For a directed change order, the contractor performs the work and then pursues an equitable adjustment for the cost and schedule impact.
Can the government change my contract without my agreement?
Within limits, yes. Under the Changes clause the contracting officer can order changes within the general scope of the contract (for example, in the drawings, specifications, or method of performance) by unilateral modification, and you must perform. What you get in return is the right to an equitable adjustment to the price and schedule for the impact of the change. The government cannot use a unilateral modification to make changes outside the contract's scope — that would be a cardinal change requiring a new procurement.
What should I do when I receive a unilateral change order?
Perform the directed work (don't treat a valid change order as optional), and immediately protect your money: give the contracting officer written notice of the cost and schedule impact, segregate and track the costs of the changed work, and submit a Request for Equitable Adjustment. The parties then normally negotiate a bilateral modification to definitize the adjustment. Follow the notice timeframes in your Changes clause so you don't weaken your recovery.
Primary Sources
- FAR 43.103 — Types of contract modifications
- FAR 43.201 — General (change orders)
- FAR 52.243-1 — Changes—Fixed-Price
Plain-English reference, not legal advice. Contract modification, options, novation, and termination rules are fact-specific, and the FAR and agency supplements are amended from time to time — always read the current FAR text, follow the notice and certification timeframes in your specific contract clauses, confirm the requirements with the contracting officer, and consult qualified counsel before relying on a modification, settlement, claim, or termination position.
Change log (1)
- LaunchedPublished the federal contract modifications, options & change management reference covering how a federal contract changes after award — the bilateral supplemental agreement and the unilateral modification (FAR 43.103), the change order under the Changes clause (FAR 52.243-1), the administrative change (FAR 43.101), the equitable adjustment and the Request for Equitable Adjustment (FAR 43.204 / 43.205), the constructive change doctrine, the options to extend the term and quantity (FAR 52.217-8, 52.217-9, and the Subpart 17.2 quantity options 52.217-6/-7), the novation and change-of-name agreements (FAR Subpart 42.12), and the terminations for convenience and default (FAR Part 49 / 52.249-2 / 52.249-8) — each with an at-a-glance quick-facts card, a when-you-see-it list, a key-features table, an SDVOSB-specific angle, a how-to-handle-it checklist, watch-outs, FAQPage, Article, Dataset, and BreadcrumbList structured data, primary-source FAR citations, and cross-links into the glossary, regulation explainers, clauses, forms, contract types, protest & dispute forums, compliance deadlines, how-to guides, FAQ, and the limitations-on-subcontracting, price-to-win, size-standard, and set-aside eligibility calculators.