Most states do not license mold work at all. Texas does, through the Department of Licensing and Regulation, and understanding the structure tells you what to ask for and what you should end up holding.
Two licences, deliberately separated
The regime creates two distinct roles.
A Mold Assessment Consultant inspects the property, takes and interprets samples, and writes the remediation protocol — the document specifying what must be done and to what standard.
A Mold Remediation Contractor executes that protocol.
Above the threshold, the same company generally cannot do both on the same project. That is inconvenient, it costs you a second engagement, and it is the most valuable feature of the whole system.
The reason is straightforward. A contractor paid by the amount of work performed has an interest in finding more work. An assessor with no financial stake in the remediation does not. Separating them means the scope is set by somebody who does not benefit from its size, and the clearance is judged by somebody who does not benefit from it passing.
The 25 contiguous square foot threshold
The line the rules turn on.
Below 25 contiguous square feet: a property owner may address it themselves, and a general contractor may handle it, without mold licensing.
At or above: licensed assessment and licensed remediation are required.
Twenty-five square feet is a patch roughly five feet by five. Two points about how it is measured that catch people out:
"Contiguous" means connected. Three separate two-square-foot patches in different rooms are not aggregated. One continuous area behind a wall is, even where only part of it is visible.
Visible growth is smaller than actual growth. A stain that measures fifteen square feet on the surface routinely turns out to be forty once the drywall is off. The measurement that matters is the actual affected area, which is why an assessment before deciding is worth having.
The Certificate of Mold Damage Remediation
This is the document to make sure you receive, and most people do not know to ask.
Where licensed remediation is performed on a project above the threshold, Texas provides for a certificate to be issued to the property owner confirming that the work was done and that clearance criteria were met.
Why it matters:
Disclosure when you sell. Texas requires sellers to disclose known mold damage on residential property. Holding a certificate converts that disclosure from an open liability into a resolved item — the damage existed, it was remediated by a licensed contractor, and an independent assessor verified it. Without one, a buyer has only your account of what happened.
Insurance. In certain circumstances an insurer may not deny coverage or increase premiums on a property solely because of mold damage that has been properly remediated and certified. Read your own policy, and keep the certificate with the property records rather than in a drawer.
Future transactions. Lenders and buyers ask. A documented remediation is a very different conversation from an undocumented one.
How to check a contractor
Licences are searchable through TDLR's public licence search, and it takes a minute.
Ask for the licence number rather than accepting "we're licensed and insured", which is a phrase rather than a fact. Then confirm the licence type matches the work: an assessment consultant licence is not a remediation contractor licence, and vice versa.
Insurance is separate from licensing. General liability and, where relevant, pollution liability. Ask to see the certificate.
What the rules do not cover
Worth knowing so you are not misled in either direction.
There is no legal limit for indoor mold spore concentrations in Texas or anywhere in the United States. No air sample result is "over the limit", because no limit exists. Interpretation is comparative, against an outdoor control sample taken the same day. Anyone quoting a threshold is inventing it.
Licensing does not certify competence at diagnosis. It sets a floor. A licensed contractor who never finds the water source is compliant and useless.
Health claims are outside the scope entirely. Nobody in this trade is qualified to tell you what a finding means for a particular person's health. That is a physician's question.
Exemptions worth knowing
The rules include exemptions, and they occasionally matter.
A property owner working on their own residence is generally outside the licensing requirement. Certain routine maintenance and cleaning activity is not treated as remediation. And work performed for an owner who intends to occupy the property is treated differently from work in rental or commercial settings in some respects.
Where you are unsure — particularly as a landlord, because rental property is where the exemptions are narrowest — it is worth asking directly rather than assuming.
What licensed work looks like from your side
If you have never been through it, the sequence is worth knowing so you can tell whether it is being done properly.
You engage an assessor. They inspect, take readings, sample where justified, and issue a report with a remediation protocol. That protocol specifies containment boundaries, engineering controls, what material comes out and to what boundary, cleaning methods for what stays, the drying standard, and the clearance criteria.
You then take that protocol to remediation contractors. Because they are all quoting the same written scope, the prices are genuinely comparable — which is the second underrated benefit of the system. Without a protocol you are comparing three different jobs that happen to have numbers attached.
The contractor performs the work. Before anything is rebuilt, and with the containment still standing, the assessor returns for clearance: visual inspection, moisture verification, and air sampling against an outdoor control.
If it passes, the certificate is issued and the rebuild starts. If it fails, the contractor corrects at their cost while the wall is still open, which is precisely why clearance happens before reconstruction rather than after.
What this means practically
If your affected area is clearly small, clearly on a hard surface, and you know exactly where the water came from and have fixed it, you can handle it.
If it is large, hidden, in a rental, part of an insurance claim, or attached to a transaction, use the licensed route. The paperwork is the product as much as the work is.
See mold inspection for what an assessment involves and clearance testing for how a job is signed off.
Get a free assessment
Tell us what you are seeing and where. We come out, find the moisture source, and put the scope and the price in writing before anything is torn out.