Other · FAR 16.603

Letter Contract (Undefinitized Contract Action)

What It Is

A letter contract is a written preliminary contractual instrument that authorizes the contractor to begin performing work immediately, before the parties have negotiated a definitive contract. It is used when the government's interest demands that work start at once but there is not enough time to negotiate a complete contract first. Letter contracts are undefinitized contract actions: they must be definitized (converted to a final contract with agreed terms and price) within a set schedule, typically within 180 days or before more than a stated percentage of the work is completed, whichever is earlier. They are tightly controlled because the contractor begins work before price is fixed.

Who Carries the Risk

Front-loaded risk for both sides — the contractor performs before price is settled, while the government commits before terms are final; the definitization schedule and a not-to-exceed limit bound the exposure.

When the Government Uses It

  • Emergencies or urgent needs where work must begin before a definitive contract can be negotiated.
  • Situations where the government's interest demands an immediate start (e.g. urgent operational requirements).
  • Only with required approvals and a definitization schedule — they are tightly limited by FAR 16.603.

Key Features

FeatureWhat It Means
Immediate authorizationAuthorizes the contractor to start work right away, before the final contract is negotiated.
Definitization scheduleMust be converted to a definitive contract on a set schedule (commonly within 180 days or before a stated percentage of work is done).
Not-to-exceed limitThe government's liability before definitization is capped at a stated maximum.
Controlled useRequires specific approvals because the contractor performs before price is agreed — used sparingly.

What It Means for an SDVOSB

Letter contracts are uncommon on routine small-business set-asides, but an SDVOSB supporting an urgent or emergency requirement may encounter one. The key cautions are practical: you are performing before the price is fixed, so track costs carefully and push to definitize on schedule — an unfavorable definitization can squeeze margins on work you have already done. Limitations on subcontracting apply to the definitized contract by its eventual work category and pricing type.

Common Pitfalls

  • Performing extensively before definitization and losing negotiating leverage on the final price.
  • Exceeding the not-to-exceed limit, beyond which the government is not obligated to pay.
  • Letting the definitization deadline slip, which can trigger reduced fee or unilateral government action.

Frequently Asked

Why would the government use a letter contract?

When its interest demands that work begin immediately but there is not enough time to negotiate a complete, definitive contract first — for example, an urgent or emergency requirement. FAR 16.603 lets the contracting officer issue a preliminary instrument that authorizes performance now, with the final terms and price to be definitized on a set schedule.

What does it mean to 'definitize' a letter contract?

Definitizing means converting the preliminary letter contract into a definitive contract with all terms agreed, including a final negotiated price. FAR 16.603 requires this on a schedule — commonly within 180 days of the letter contract or before more than a stated percentage of the work is completed, whichever is earlier. Until then it is an undefinitized contract action with a not-to-exceed liability limit.

Primary Sources

Plain-English reference, not legal advice. Contract-type selection is a contracting-officer judgment and the FAR is periodically amended — always confirm the contract type, clauses, and how the limitations on subcontracting are measured against the solicitation and your contracting officer before relying on this.

Last updated Update cadence: Quarterly, plus on FAR amendment
Change log (1)
  1. LaunchedPublished the federal contract types reference covering the pricing and delivery arrangements an SDVOSB encounters on set-asides — firm-fixed-price (FFP), fixed-price with economic price adjustment (FP-EPA), fixed-price incentive (FPIF), the cost-reimbursement family (CPFF, CPIF, CPAF), time-and-materials and labor-hour, the indefinite-delivery vehicles (IDIQ, requirements, definite-quantity), and letter contracts — each with a who-carries-the-risk callout, a key-features table, an SDVOSB-specific angle tying the type to the limitations on subcontracting, common pitfalls, FAQPage, Article, Dataset, and BreadcrumbList structured data, primary-source FAR Part 16 citations, and cross-links into the glossary, regulation explainers, how-to guides, FAQ, and the limitations-on-subcontracting and price-to-win calculators.

Related Contract Types

The Rules Behind It

13 CFR § 125.6Limitations on Subcontracting

Put It Into Practice

How to Find and Bid SDVOSB Set-Aside Contracts

Terms Used on This Page

FFPCost-Reimbursement Contract

In the FAQ Knowledge Base

What types of contracts do SDVOSBs typically perform?
How do SDVOSBs handle contract modifications?
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