Guide
Insurance requirements for an excavation subcontractor
There is one exclusion that matters more for excavation than any coverage limit on the page, and the certificate will not show you whether it applies.
Ask whether the policy carries the XCU exclusion — explosion, collapse and underground damage. For excavation that exclusion removes most of what you are actually hiring insurance for.
Key takeaways
- XCU stands for explosion, collapse and underground property damage. Those three are the excavation losses. A policy that excludes them can still show a $1M limit and cover almost nothing that is likely to happen.
- It is a standard exclusion, not a fringe one. Plenty of contractor policies carry it, and it is priced out rather than being an error. The question is whether this policy has it, not whether such policies exist.
- It does not appear on the ACORD 25. There is no XCU box. The only way to know is to ask the issuing agent or read the policy.
- Underground utility strikes are the common version. A cut fiber line is a claim with no injury, no visible damage and a very large number attached.
- Trenching has its own safety regime. OSHA requires a competent person for excavation work, and that requirement is about the crew rather than about the certificate.
By the Sealinn team · 2 min read · Updated August 2026 · Written for general contractors
What XCU removes
XCU is shorthand for three exclusions that often travel together on a commercial general-liability policy: explosion, collapse, and underground property damage. Read them against what an excavation crew actually does and the problem is immediate — blasting, a trench wall or an adjacent foundation giving way, and a bucket through something buried are not edge cases for this trade. They are the trade.
A certificate showing a $1,000,000 per-occurrence limit is telling you the truth. It is simply not telling you whether the three things most likely to generate a claim are inside that limit or outside it.
The question, verbatim
“Does this policy include coverage for explosion, collapse and underground property damage (XCU), or are any of the three excluded?” Send it to the issuing agent, keep the reply, and file it with the certificate. It is one line and it is the single most useful thing you can ask about an excavation sub's insurance.
Underground strikes, the common case
The dramatic version of the U is a gas line. The frequent version is a fiber-optic or communications cable, where nobody is hurt, nothing looks broken, and the bill arrives from a utility company that has computed its loss carefully. Locate-service tickets are the operational answer to that risk; the insurance answer is whether the U is excluded. Both are worth having, and neither substitutes for the other.
The neighbor's building
Collapse claims frequently involve property nobody on the job owns — an adjoining structure that settles because of work on your side of the line. That makes the owner of the damaged building a third party with a direct claim, and it is the situation in which being a properly endorsed additional insured on the excavator's policy stops being paperwork and starts being the difference.
Trenching, which is a safety question with your name on it
OSHA requires a competent person — someone with the authority to stop work — to inspect excavations, and the trenching standard is one of the most frequently cited in construction. On a multi-employer site the general contractor's exposure to that is real regardless of whose crew is in the trench, so the safety paperwork you collect matters here in a way it does not for a trade working at grade.
Everything else, and the other trades
The general checklist — coverages, endorsements, the waiver, the W-9 — is on what to require before a sub starts. The trade-specific line is different for each: roofing turns on products-completed operations, plumbing on water damage, electrical on the license.
Where this comes from
- ACORD — Certificate of Liability Insurance (form 25)
- ISO — Commercial General Liability Coverage Form (CG 00 01 occurrence / CG 00 02 claims-made)
- Occupational Safety and Health Administration — 29 CFR 1926.32 — Definitions (competent person, 1926.32(f))
- Occupational Safety and Health Administration — Outreach Training Program (OSHA 10 / OSHA 30)
The four jobs, done for you.
Sealinn reads each certificate, checks it against your rules, chases renewals before they lapse, and keeps the record.