Supplier Qualification: What to Check Before You Sign a Contract

Contractor prequalification is the process of evaluating whether a contractor meets your organization's minimum standards for insurance coverage, safety performance, licensing, and financial stability before awarding work. It is distinct from procurement, which evaluates price and technical capability. Prequalification is specifically about risk.

Prequalification processes range widely in formality. Some organizations manage them entirely in-house through document collection and internal review. Others use third-party platforms such as ISNetworld, Avetta, or Veriforce (formerly PEC Premier), which centralize document collection, grade contractor submissions, and make results available to subscribing owners. Oil and gas, utilities, and large industrial manufacturers are the most common users of these platforms.

This article covers the core criteria and how to structure a process that holds up over time.

Insurance Coverage

What to request. Ask for a current ACORD 25 Certificate of Liability Insurance. Review the coverage types and limits, confirm the policy dates, and check the named insured against the contracting entity.

Minimum limits. Your contract should define the minimum requirements. For general commercial work, $1 million per occurrence / $2 million aggregate is a common general liability floor. For higher-hazard work, construction, or work near processing equipment, requirements often run $5 million or more per occurrence. Workers' compensation should show statutory limits and should cover the states where the contractor's employees will actually work. If contractor vehicles will be on-site, auto liability should also be included.

Additional insured status. Being listed as the certificate holder on an ACORD 25 gives you a copy of the certificate. It does not make you an additional insured. Additional insured status requires an endorsement attached to the underlying policy. ISO endorsements CG 20 10 (ongoing operations) and CG 20 37 (completed operations) are the standard forms. Most risk programs require both: CG 20 10 covers the period while the contractor is actively working, and CG 20 37 extends coverage to liability that surfaces after the work is complete but arises from how it was performed. Request the actual endorsement copies, not just the ACORD 25.

Verification. A certificate can be issued with inaccurate information. For high-value or high-hazard contracts, contact the contractor's carrier directly to confirm the policy is active and has not been cancelled or modified.

Safety Performance

TRIR. The Total Recordable Incident Rate measures the frequency of OSHA-recordable injuries and illnesses per 100 full-time equivalent workers:

TRIR = (recordable incidents x 200,000) / hours worked

Request OSHA 300 Logs and 300A Summaries for the past three calendar years. Calculate the three-year TRIR and compare it against the BLS annual average for the contractor's primary NAICS code. The Bureau of Labor Statistics publishes this data through the annual Survey of Occupational Injuries and Illnesses. For context, the 2024 all-private-industry average is 2.3. Construction averages approximately 3.1 and manufacturing approximately 3.4.

DART rate. The Days Away, Restricted, and Transfer rate uses the same formula as TRIR but counts only incidents resulting in days away from work or restricted or transferred duty. DART rates measure severity, not just frequency, and are a useful complement to TRIR.

EMR. The Experience Modification Rate is a workers' compensation underwriting factor that adjusts premiums based on an employer's actual loss history compared to expected losses for similarly classified employers. A 1.0 is industry average. Values below 1.0 indicate a better-than-average record; values above 1.0 indicate worse.

NCCI calculates the EMR in most states. California uses the WCIRB (where it is called the X-Mod). Pennsylvania, Texas, New York, and a handful of other states use their own rating bureaus. The calculation covers a three-year window that excludes the most recently completed policy year. An EMR effective in 2026 reflects loss data from 2022, 2023, and 2024. The formula weights claim frequency more heavily than severity, which means frequent small claims can elevate the EMR more than a single large claim.

Common prequalification thresholds are 1.0, 0.90, or 0.85 depending on the hazard level of the work and the organization's risk tolerance. Many prequalification platforms automatically flag contractors with an EMR above 1.0.

OSHA citations. Ask contractors to disclose any OSHA citations received in the past three years, including the citation type (other than serious, serious, repeat, willful) and the corrective actions taken. Willful and repeat violations are disqualifying criteria for most formal prequalification programs.

Licensing and Credentials

Verify that the contractor holds all licenses required for the work type and jurisdiction. Electrical, plumbing, HVAC, and crane operation are licensed trades in most states, though specific requirements vary. Some licenses are state-issued; others are issued by local jurisdictions.

Document the expiration date for each credential, not just whether it exists. OSHA 10 and OSHA 30 cards expire; crane operator and rigging certifications have continuing education requirements. A certification that expired six months ago is not the same as a current one.

Third-Party Prequalification Platforms

ISNetworld, Avetta, and Veriforce are the three largest platforms for contractor prequalification in North America. Each operates on a subscription model: contractors pay to maintain a profile and submit required documents; owner organizations subscribe to view contractor data and define their own acceptance criteria.

On these platforms, contractors typically submit insurance certificates, OSHA 300 logs, written safety programs, EMR documentation, and answers to operator questionnaires. The platform grades or flags the submission, and the owner defines what grade is acceptable. For organizations managing large contractor populations, these platforms reduce the administrative burden of document collection and initial review, though they do not replace internal verification for higher-risk situations.

Documenting Decisions

Record prequalification decisions. When a contractor renews, compare updated metrics against the prior period. A contractor whose TRIR has been trending upward over three years represents a different risk profile than one who has maintained a consistent rate, even if both currently meet the threshold.

When a contractor falls short in one area but is conditionally approved pending correction, document what gap was identified, what correction is required, and what the deadline is. When a waiver is granted to approve a contractor who does not meet a threshold, document who authorized the waiver and why.

Prequalification requirements are not standardized across industries. Criteria appropriate for utility work may differ substantially from process plant construction or food manufacturing. The criteria above reflect common practice across several sectors; define thresholds based on the hazard level of the work and the requirements of your liability program.