Clin

Contract Line Item Number (CLIN) is a designation used in government procurement contracts to identify and price distinct deliverables or services within a single contract. Each CLIN represents a discrete item, service, or milestone and typically includes a description, quantity, unit of issue, and price. CLINs enable separate tracking of performance, acceptance, invoicing, and payment for each deliverable.

CLINs are used to structure contracts for clarity and accountability. They allow agencies to solicit, evaluate, and award offers for individual items, bundle related items, or designate base periods and option periods. A contract may include multiple CLINs, sometimes with sub-CLINs to break down complex requirements. In some programs, CLINs are labeled to indicate base and option components, such as A-CLINs for the base period and B-CLINs for option periods.

Invoicing and administration are typically organized around CLINs. Contractors submit invoices against specific CLINs, and government buyers use CLIN data to verify delivery, performance, and acceptance. This structure supports progress payments, milestone payments, or final settlement as specified in the contract.

While CLIN usage is most common in United States federal procurement and defense contracting, many government and international programs adopt similar line-item concepts to manage scope, pricing, and compliance. Related concepts include sub-CLINs, SLINs for services, and the broader contract administration framework under applicable regulations such as the Federal Acquisition Regulation.