If you manage a property in California, window cleaning can feel like a simple maintenance item until you think through the risk. Vendors may be working at height, around tenants and parked cars, and near glass, landscaping, and building finishes. The easiest way to reduce problems is to standardize what you require up front and make sure the Certificate of Insurance matches the work being performed.

This guide is written for property managers and vendor compliance reviews. It explains the core coverages you should expect, what to look for on a COI, and the common red flags that get vendors rejected.

The Short Answer

At a minimum, most properties in California should require workers’ compensation when the vendor has employees, general liability, and auto liability if vehicles are on-site. Larger sites, higher-risk access, or multi-building portfolios often add an umbrella policy and specific COI endorsements like additional insured status and waiver of subrogation, depending on your contract and risk tolerance.

Workers’ Compensation

Workers’ compensation is the most important “go/no-go” item for many property managers because it deals with jobsite injuries. In California, employers are required to carry workers’ compensation for their employees, even if they only have one employee.

If a vendor says they do not have workers’ comp because they have “no employees,” you should still treat that carefully. Some companies are truly owner-only, but many vendors use helpers, part-time labor, or subcontractors, and that is where properties get exposed. A good compliance process asks for clear documentation that aligns with your vendor agreement and your building’s requirements, rather than relying on a verbal statement.

General Liability

General liability is what covers many of the common “oops” moments that can happen during window cleaning: accidental property damage, broken glass, overspray issues, or third-party injury claims. California does not have one universal rule that forces every contractor to carry general liability in all situations, but it is widely required by commercial properties and contracts, and it is considered a baseline expectation for professional vendors.

For commercial sites, you will commonly see general liability limits written into contracts at one million dollars per occurrence and two million dollars aggregate. Your property may require higher limits depending on height, foot traffic, or the type of building.

Auto Liability

If the vendor is bringing vehicles onto your property, auto liability matters. This is true even if they are not “driving as part of the scope,” because vehicles are still part of the risk profile on a commercial site. Properties commonly require auto liability for vendor vehicles and may specify minimum limits in their vendor agreements.

Umbrella Or Excess Liability

Umbrella or excess liability is a way to increase the total coverage above the general liability and auto policies. Many properties use umbrella requirements for higher-risk work, larger commercial footprints, or any situation where access is more complex. The practical way to think about umbrella coverage is that it is there for the rare event that becomes expensive fast.

What To Look For On The Certificate Of Insurance

A COI is only a summary, but it’s still where most compliance mistakes show up. The basics you should verify are that the named insured matches the vendor’s legal business name, the policy dates are current, and the coverage types and limits match your requirements.

If your contract requires it, you may also ask for endorsements that change how claims are handled. “Additional insured” is typically used so your ownership or management entity is protected under the vendor’s policy for covered claims tied to the vendor’s work. “Primary and non-contributory” is generally used to confirm the vendor’s insurance responds first rather than pulling your property’s policy into the claim.  “Waiver of subrogation” is often requested to reduce the likelihood of the vendor’s insurer pursuing recovery against your side after paying a loss.

If your agreement requires these items, it is smart to confirm they are supported by endorsements when needed, not just typed into a certificate “description” box. A COI can be incomplete or misleading if the endorsement is not actually issued.

Common Red Flags That Get Vendors Rejected

An expired COI is the simplest and most common failure. The second most common issue is missing workers’ comp when the vendor clearly has employees or regularly uses labor. Another red flag is when the COI business name does not match the vendor’s contract name, website, invoices, or license records. That mismatch creates confusion during claims and can invalidate your compliance process.

You should also be cautious when a vendor provides general liability but no auto liability while still driving vehicles on-site, or when the limits do not match what your agreement requires. Finally, if the vendor cannot provide updated certificates quickly or consistently, that is often a sign of disorganization that will show up again during scheduling, tenant coordination, or jobsite documentation.

A Simple Insurance Requirement Template You Can Use

Here is clean, copy-ready wording you can paste into a vendor onboarding email or compliance checklist.

Vendor shall maintain workers’ compensation insurance as required by California law for all employees performing work. Vendor shall maintain commercial general liability insurance on an occurrence basis with limits not less than one million dollars per occurrence and two million dollars aggregate, or higher if required by the property’s vendor agreement. Vendor shall maintain automobile liability insurance for any owned, hired, or non-owned vehicles used in connection with the work. Upon request, vendor shall provide a certificate of insurance showing current policy dates and limits, and shall provide additional insured status for the property ownership/management entity when required by contract. Vendor shall provide updated certificates upon renewal and prior to performing work on-site.

The Practical Bottom Line For Property Managers

If you only enforce one thing consistently, make it workers’ compensation for employee-based vendors and a current, matching COI. From there, general liability and auto liability are the baseline you’ll see on most professionally managed properties, with umbrella coverage and endorsements used when the building, access, or contract terms increase the risk.