The 7 COI Endorsements Fiber Subs Need.
Clear GC Pre-Qualification on the First Try.

A subcontract agreement contains indemnity language that pushes liability for the sub’s work down to the sub. The endorsements are how your insurance policy mirrors that indemnity — making sure the GC and the property owner are covered by your policy when something goes wrong on your scope.

A naked COI (no endorsements) tells the GC that you have insurance, but it doesn’t prove their interests are protected. Their risk management team will reject the COI, the project manager will tell you to fix it, and you’ll lose 1–2 weeks of mobilization time while your broker chases your carrier for endorsements your policy may or may not even support. The contractors who win the most work are the ones whose brokers can issue a fully-endorsed COI within a few hours of a request.

Names the GC (and often the property owner) as an additional insured on your General Liability policy for liability arising out of your ongoing operations at their project. This is the most-requested endorsement in all of commercial subcontracting. (For installers specifically — not OSP layer crews — see our dedicated page on insurance for cable installers for what each endorsement looks like on a typical installer COI.) Modern wording is CG 20 10 (10/01) or CG 20 38 (12/19). Some primes specifically ask for the 2013 edition (CG 20 10 04 13) because it limits coverage to liability caused by your acts or omissions — both you and the prime should be comfortable with this version.

Extends additional insured status to claims arising after your scope is completed (failed splice years later, defective install causing a fire, etc.). This is the endorsement most often missed by small contractors — their GL provides Ongoing Ops AI but not Completed Ops. Hyperscaler data center GCs, telecom primes, and BEAD-funded projects all require both. Form number: CG 20 37.

Prevents your insurance carrier from suing the GC to recover what they paid out on a claim, even if the GC was partly at fault. GCs require this so they aren’t indirectly sued by your insurer after they help you defend a claim. Form number: CG 24 04. Some carriers add a blanket waiver of subrogation endorsement that covers all parties named in your written subcontracts.

Specifies that your policy pays first before any of the GC’s insurance applies, and that the two policies do not share the loss. This is increasingly mandatory on hyperscaler and BEAD subcontracts. Without it, the GC’s own insurance might be tagged on a loss caused by your work — raising their experience modifier and their premium. Form: CG 20 01 04 13 is the most common modern version.

Splits your General Liability aggregate so that each project gets its own dedicated aggregate limit, rather than sharing one annual aggregate across every project you’re running. Why it matters: if you have a $2M aggregate and one $2M loss on a different job, you’re left with $0 of coverage on the GC’s current project. Per-project aggregate prevents this. Form: CG 25 03 (Designated Construction Project Aggregate Limit) or CG 25 04 (per location). Many large GCs require this in contract.

Most fiber contractors don’t own enough commercial vehicles to think of this as a real issue — but the second one of your employees uses a personal vehicle for work, you have a non-owned auto exposure. If your business doesn’t own the vehicle (rented bucket truck, employee’s personal pickup), only Hired & Non-Owned Auto coverage protects you. Every GC in 2026 looks for this on the COI, and the absence of it is one of the most common rejection reasons for small subs. Coverage is usually written on a Business Auto policy; the endorsement form is CA 99 33 or built into a Business Auto policy from the start.

Same concept as the GL waiver, applied to your workers’ comp policy. Prevents your comp carrier from suing the GC to recover medical and indemnity payments after one of your employees is hurt on the GC’s site. Practically every commercial subcontract requires this. Form: WC 00 03 13 (blanket) or state-specific equivalents. In states like California and Pennsylvania, the WC waiver is highly regulated — verify your carrier can issue it before you bid.

Looking at hundreds of fiber-contractor COI submissions to telecom GCs and hyperscaler data center primes, the same five issues account for nearly every rejection:

Ask your broker for a declarations page and endorsement schedule for your GL, Auto, and WC policies. Pull every endorsement form number. Compare against the 7-endorsement list above. Identify what’s missing.

The contractors who turn around COIs fastest have a pre-built ACORD 25 template with: their company info, current policy numbers and limits, and a standard description box pre-populated with the form numbers (CG 20 10, CG 20 37, CG 24 04, CG 20 01, CG 25 03, CA 99 33, WC 00 03 13) plus a blanket additional insured wording reference. The certificate holder name and project description gets filled in per request.

The single largest operational advantage in fiber subcontracting is a broker who can issue customized COIs same-day or within hours. Brokers who take 2–5 business days to issue a COI are why subs lose bids. If you’re bidding active work, your broker should be on call to issue endorsements when a request lands.

Before signing any subcontract, read the insurance requirements section against your COI. If the contract requires a form your COI doesn’t reference, fix the COI before you sign the subcontract, not after. Mid-project insurance changes are stressful, often expensive, and can delay mobilization.

• Additional Insured — Ongoing Operations (CG 20 10 or CG 20 38)
• Additional Insured — Completed Operations (CG 20 37)
• Waiver of Subrogation — GL (CG 24 04)
• Primary & Noncontributory wording (CG 20 01)
• Per-Project Aggregate (CG 25 03)
• Hired & Non-Owned Auto (CA 99 33 or built-in to Business Auto)
• Workers’ Comp Waiver of Subrogation (WC 00 03 13 or state equivalent)

• Underground utility strike coverage is NOT excluded from your GL
• Pollution liability is available (or via separate CPL policy) for directional drilling and trenching scopes
• Inland marine covers your fusion splicers, OTDRs, MPO testers, and reels at remote sites
• Tools, mobile equipment, and reels in transit are covered

• Build a pre-populated ACORD 25 COI template with your company info, policy numbers, limits, and standard endorsement form numbers
• Confirm your broker can issue customized COIs within a few hours, not days
• Establish a subcontract review process — check insurance requirements before signing
• Keep digital copies of every issued COI for the duration of every project