FAR 16.603-3—Limitations.
Plain-English Summary
FAR 16.603-3 sets the limits on when a letter contract may be used and what it may not do. It covers three main subjects: the threshold approval required before using a letter contract, the prohibition on obligating the Government beyond available funds, the restriction on using a letter contract without required competition, and the limits on later amending a letter contract to add new work. In practice, this section exists because letter contracts are an exception tool for urgent starts, but they carry risk if used too broadly or without proper controls. The rule forces contracting officials to justify why no other contract type is suitable, ensures fiscal discipline, preserves competition requirements, and prevents agencies from using amendments to bypass normal acquisition procedures. For contractors, it means early work under a letter contract is provisional and tightly bounded; for contracting officers, it means careful documentation, funding checks, and scope control are essential before and after award.
Key Rules
Written approval required
A letter contract may be used only after the head of the contracting activity, or a properly designated official, makes a written determination that no other contract is suitable. This is a threshold safeguard and not a routine approval; the file must show why a definitive contract or other approach cannot meet the need.
No excess funding commitment
The Government may not commit itself through a letter contract to a definitive contract amount that exceeds the funds available when the letter contract is executed. This means the contracting officer must ensure the initial obligation stays within available funding and cannot rely on later funding to cure an overcommitment.
Competition rules still apply
A letter contract cannot be used without competition when competition is required by FAR part 6. The urgency or provisional nature of a letter contract does not waive competition requirements unless another valid statutory or regulatory exception applies.
No new requirements by amendment
A letter contract may not be amended to cover a new requirement unless that requirement is inseparable from the existing letter contract. If an amendment is allowed, it is treated like a new letter contract and must meet the same approval, funding, and competition limitations.
Inseparable work only
The only permissible expansion by amendment is work that cannot reasonably be separated from the original letter contract requirement. This prevents agencies from using a pending letter contract as a vehicle to add unrelated or newly identified work without following normal acquisition procedures.
Responsibilities
Head of the Contracting Activity (HCA) or Designee
Make the required written determination that no other contract is suitable before a letter contract is used. This official must ensure the decision is documented and supported by the acquisition circumstances.
Contracting Officer
Verify that the letter contract is within available funds, that competition requirements are satisfied or properly excepted, and that any amendment does not add a new requirement unless it is inseparable from the original work. The contracting officer must also ensure any amendment is processed under the same controls as a new letter contract.
Agency
Maintain acquisition policies and oversight that prevent improper use of letter contracts, including ensuring the approval chain, funding controls, and competition requirements are followed. The agency must support the contracting officer with legal, fiscal, and acquisition review as needed.
Contractor
Perform only the work authorized under the letter contract and any properly approved amendment. The contractor should not assume broader scope, additional funding, or conversion to a definitive contract beyond what is formally authorized.
Practical Implications
Letter contracts are an exception, not a convenience tool; if the file does not clearly show why no other contract is suitable, the award is vulnerable to challenge or internal review findings.
Funding must be tightly controlled at the time of execution. A common pitfall is treating the letter contract as a placeholder for a larger future obligation without having funds available for that commitment.
Competition cannot be sidestepped just because the requirement is urgent. If part 6 competition applies, the agency must either compete the action or have a valid exception.
Scope creep is a major risk. Adding new work through amendment can turn a limited urgent-start instrument into an improper substitute for a new procurement.
Contractors should treat work under a letter contract as provisional and carefully track what is authorized, because later conversion to a definitive contract or amendment is not automatic and remains subject to the same restrictions.
Official Regulatory Text
A letter contract may be used only after the head of the contracting activity or a designee determines in writing that no other contract is suitable. Letter contracts shall not- (a) Commit the Government to a definitive contract in excess of the funds available at the time the letter contract is executed; (b) Be entered into without competition when competition is required by part 6 ; or (c) Be amended to satisfy a new requirement unless that requirement is inseparable from the existing letter contract. Any such amendment is subject to the same requirements and limitations as a new letter contract.