How Does TWIA Windstorm Insurance Work for Commercial Property?

What Is TWIA, and What Does It Insure?

The Texas Windstorm Insurance Association (TWIA) is the insurer of last resort for wind and hail on the Texas coast. It covers damage from windstorm and hail only. It does not cover fire, theft, liability or flood.

The Legislature created TWIA in 1971, after hurricanes made coastal coverage hard to find. TWIA is not a state agency and gets no state general revenue. The Texas Department of Insurance (TDI) regulates it under Texas Insurance Code Chapter 2210. As of June 30, 2026, TWIA insured 288,676 properties with about $128.3 billion of insured value, according to its own fact book.

For a commercial owner, TWIA is usually one piece of a larger program. Your main commercial property policy covers fire and other causes of loss. On the coast it often carries a windstorm exclusion, an endorsement that removes wind and hail. TWIA fills that wind and hail gap, and flood needs a policy of its own.

Is My Commercial Property Eligible for TWIA?

You need four things. The property must be inside TWIA's designated area and in insurable condition. It must meet the windstorm building code for its area. And you need a qualifying declination.

Where TWIA Writes

TWIA's designated area, often called the catastrophe area, includes all 14 first-tier coastal counties: Aransas, Brazoria, Calhoun, Cameron, Chambers, Galveston, Jefferson, Kenedy, Kleberg, Matagorda, Nueces, Refugio, San Patricio and Willacy.

It also takes in part of Harris County. That part is only the area east of Highway 146 and inside the city limits of La Porte, Morgan's Point, Pasadena, Seabrook and Shoreacres. The rest of Harris County, including most of Houston, is outside TWIA's area. There, wind and hail coverage comes from private insurers.

The Declination Requirement

Before TWIA writes new coverage, you or your agent need at least one declination. A declination is a refusal from an insurer authorized in Texas that is writing wind and hail somewhere in the first-tier coastal counties. TWIA states that surplus lines insurers do not qualify.

Two kinds of refusal count as a declination. One is a flat refusal to write wind and hail on the property. The other is an offer more restrictive than TWIA's, such as a much higher deductible or no replacement cost. A higher premium alone does not count. A wind exclusion on another policy is not enough proof either, because TWIA may treat it as your choice to leave wind out. For renewals, TWIA needs a new declination every three calendar years. Agents must keep proof for at least five years.

Flood Insurance in V Zones

TWIA requires flood insurance when three conditions all apply. First, any part of the property is in an NFIP V, VE or V1–V30 zone, the zones with added wave hazard. Second, the structure was built, altered, remodeled or enlarged after September 1, 2009. Third, NFIP coverage is available. Maintenance, repairs and re-roofing generally don't trigger the rule. Our commercial flood guide covers flood in more detail.

Why Does My Building Need a Windstorm Certificate?

To qualify, a building generally needs a certificate of compliance. The certificate shows it meets the windstorm building code for its area. For commercial property, expect to need one for the building and for any work done on or after January 1, 1988.

The rule covers structures built, altered, remodeled, enlarged, repaired or added to on or after that date. A new roof, new windows or doors, or an addition can each need their own certificate. The WPI-8 certificate of compliance comes in three versions:

TWIA offers a surcharge path for some uncertified buildings, but only for residential property. Commercial buildings generally need the certificate itself. The practical lesson is to start the windstorm inspection process before work begins. You can certify finished work with a WPI-8-E. That route can take more paperwork, because some building parts are already covered up.

How Does TWIA Fit With My Private Property Policy?

Most coastal commercial programs use two or three policies, and each covers a different cause of loss. The goal is no gaps and no overlap. The table shows the common pattern.

Coordination matters most after a hurricane, when wind and water hit the same building. The wind insurer pays for wind damage and the flood insurer for flood damage. Dated photos taken before and after the storm help each adjuster separate the two.

Limits are the next question. TWIA's Q2 2026 fact book lists $4,424,000 as the maximum for a commercial structure and its contents combined. TWIA reviews its limits each year, so confirm the current figure at renewal. If a building is worth more, you need more wind coverage above TWIA. That extra layer is often placed with surplus lines insurers.

Also check how you'd recover lost income after a wind loss. If your private policy excludes wind, its business income coverage may not respond to a wind loss either. Ask your agent how wind-caused income loss is covered in your program.

How Do TWIA Deductibles Work?

TWIA policies carry a wind and hail deductible. For commercial property, TWIA's current rating rules offer 1%, 2% or 5% of each item's insured amount, per occurrence, with a $1,000 minimum. Your declarations page shows your exact deductible. TWIA can change its options, so confirm them at renewal.

A percentage deductible is figured on the insured value, not on the size of the loss. A small percentage of a large value can add up to a big number. So write your deductible down in dollars, for every building.

Lenders often cap the deductible you may carry. Check your loan documents before you raise a deductible to lower the premium; lender insurance requirements often set a ceiling. Our deductibles guide walks through more examples. If your wind coverage comes from a private policy, it may use a separate named storm deductible. Compare how each deductible is triggered and measured, not just the percentage.

How Is a TWIA Claim Different From a Regular Property Claim?

TWIA claims follow their own process in Insurance Code Chapter 2210. Both sides have fixed deadlines. TWIA says the Texas prompt payment law (Chapter 542) and the unfair settlement practices law (Chapter 541) do not apply to its claims. The Chapter 542A pre-suit notice rules do not apply either.

Two TWIA deadlines often catch owners off guard. If you dispute the amount, you generally must demand appraisal within 60 days of TWIA's written decision. Under §2210.574, missing that window waives your right to contest the amount. If your policy includes replacement cost, you generally must finish repairs and send proof within 545 days after you receive TWIA's decision (§2210.5741).

TWIA also has a supplemental payment process. If you find more damage or have new information, you can send it in for review. You don't have to start appraisal or file a lawsuit to do that. TWIA reports that about 4% of its claims involve a dispute, and 88% of those involve an appraisal request. These are statutory deadlines, not legal advice. If a dispute is building, talk with a Texas attorney early.

What Should Coastal Owners Do Before Storm Season?

Most TWIA problems show up at claim time but start months earlier. This checklist helps you find them while there is still time to fix them.

1. Confirm each building is inside TWIA's area. In Harris County, check the city limits as well as Highway 146.
2. Find or order a windstorm certificate for each building. Do the same for each roof, window project or addition since 1988.
3. Check the date of your last declination. Renewals need a new one every three calendar years.
4. Compare TWIA's commercial maximum to each building's rebuilding cost, and plan for any gap.
5. Check whether you need flood insurance under TWIA's V-zone rule or your loan documents.
6. Write down each wind and hail deductible in dollars, per building.
7. Take dated photos of roofs, windows and interiors before hurricane season.
8. Save TWIA's claim and appraisal deadlines where your team can find them.

For the bigger picture, our Texas property risk guide covers coastal exposures. If you'd like, we can review your wind, flood and property policies side by side. Contact us when you're ready.

Questions Owners Ask

Sources

1. TWIA: Coverage area
2. TWIA: Declination requirement
3. TWIA: Flood insurance requirement
4. TWIA: Windstorm certification
5. TWIA Fact Book, Q2 2026 — Maximum liability limits, policy counts, claim dispute figures (data as of June 30, 2026)
6. Texas Insurance Code Chapter 2210 (TWIA) — §§2210.014, 2210.202, 2210.203, 2210.205, 2210.573–2210.577 (including 2210.5731 and 2210.5741)
7. Texas Insurance Code §542A.002 — Chapter 542A does not apply to TWIA
8. TWIA Rating Rules (effective February 13, 2024) — Commercial deductibles: 1%, 2% or 5% per item, per occurrence; $1,000 minimum