Does a mold remediation company need a license?

It depends on the state. Florida, Texas, New York, Louisiana, the District of Columbia, and Tennessee above a certain job size license mold work. Most states do not. Check whether your state licenses mold work before you hire.

What certifications should a mold remediation company have?

Industry certifications such as IICRC and ACAC credentials show that a technician has been trained in the standard remediation process. They are separate from a license. Ask who on the crew holds them and whether that person will be on your job.

What insurance should a mold remediation company carry?

General liability, workers compensation, and pollution liability that specifically covers mold. Ask for the certificate of insurance and confirm the mold coverage with the company's agent, because many general liability policies exclude it.

Should the same company inspect and remediate?

The cleaner arrangement separates them. An independent inspector writes the scope and returns for clearance, and remediation companies bid on that scope. Where one company does both, get the moisture readings and square footage in writing and have them confirmed.

How to choose a mold remediation company: license, scope, questions

Choosing a mold remediation company comes down to a short set of checks: whether your state licenses the work, what insurance the company carries, what its certifications mean, whether it will put a scope in writing, whether it keeps inspection separate from remediation, and whether it will submit to independent clearance. This guide walks through each one and ends with the questions to ask before you sign.

Check whether your state licenses mold work

Mold remediation is licensed in a few states and unregulated in most. Florida, Texas, New York, Louisiana, and the District of Columbia license mold assessors and remediators, and Tennessee licenses the work above a certain job size. In those places, a license number is the first thing to ask for, and the state’s licensing website confirms it.

Elsewhere, no mold license exists, and anyone with a van and a fogger can call themselves a remediation company. A general contractor license may still apply to the demolition and rebuild portions of the work, and local business licenses still apply. Check whether your state licenses mold work before you start calling, and ask any company you call what it holds.

The absence of a license requirement makes the rest of this guide matter more. Insurance, certification, scope, and clearance are the substitutes.

Insurance and certifications

Neither substitutes for a license, and both matter more where no license exists.

Insurance

Ask for a certificate of insurance and read it. Three coverages matter.

General liability covers damage the crew does to your property. Many general liability policies exclude mold, which is a known gap in this trade. Pollution liability, sometimes sold as environmental or contractors pollution coverage, is the policy that covers mold specifically. Ask whether the company carries it and ask to see mold named on the certificate.

Workers compensation covers the crew if someone is hurt in your house. Without it, that claim can land on the homeowner.

Call the agent named on the certificate to confirm it is current. A company that hesitates to provide a certificate has answered the question.

Certifications

Industry certifications show that a technician has been trained in the standard remediation process. IICRC and ACAC credentials are the most common examples. They are issued by trade organizations, they require coursework and exams, and they are different from a state license.

Two questions make a certification meaningful. Who on the company holds it? And will that person be on your job, or supervising it? A certificate on the owner’s wall says little about the crew that shows up. Ask for the name and the credential of the person who will lead the work.

A written scope

A sound company puts the scope in writing before it starts, and the scope contains the affected areas with square footage, the moisture source and who fixes it, containment and negative air, the materials to be removed, cleaning and antimicrobial treatment, drying, the clearance method, and exclusions. The guide to reading a mold remediation estimate covers each line.

A company that gives you a total with no scope, a verbal price, or an estimate that lists no square footage has given you nothing to compare or to enforce. Walk away from that one early.

Compare the scope’s math with published bands. This Old House prices remediation at $10 to $25 per square foot, with a typical job at $1,200 to $3,750 and an average of $2,300. Fixr prices it at $10 to $30 per square foot and a typical job at $1,500 to $9,000, with an average of $3,500. The mold remediation cost page shows the full set, and the planning calculator applies them to your square footage. A scope priced far outside those bands needs an explanation.

Separate inspection from remediation

The company that measures the square footage should have no stake in how large it is. An independent inspector who sells no remediation writes the scope, remediation companies bid on that scope, and the same inspector returns for clearance. Fixr notes that remediation firms price a standalone inspection at $450 to $800, about the same as an independent inspector, so the separation costs little.

Where one company does both, the arrangement can still work. Get the moisture readings and the measured area in writing, and have a second company or an independent inspector confirm them before you sign. The inspection versus testing guide explains what an inspection includes and what testing adds.

References and recent work

Ask for addresses or contacts from recent jobs similar to yours: same kind of space, same kind of source. Call them and ask whether the source was fixed, whether the mold returned, and whether the final invoice matched the estimate. A company that has done attic jobs all year and is bidding your crawl space is learning on your house.

Online reviews are a starting point, and they are also the easiest thing in this trade to manufacture. Weigh a direct conversation with a past customer above any star count.

Clearance

A sound company expects its work to be checked by someone else. Ask whether the company will work to an independent clearance test, who performs it, what it costs, and what happens if the first test fails. Fixr prices air testing at $500 to $700 for two samples plus lab analysis, with extra samples at $60 to $80.

A company that offers only its own walk-through as clearance, or that promises the air will “pass,” is asking you to take its word for the one thing you cannot see. A company that writes “work continues until independent clearance is achieved” into the scope has made a promise it can keep.

Questions to ask

Put these to each company before you sign, and write down the answers:

Does my state license mold work, and what license do you hold?
Can I see your certificate of insurance, and does it name mold under pollution liability?
Who on the crew holds an industry certification, and will that person lead my job?
Where is the moisture coming from, and who fixes it?
What is the measured square footage, and how did you measure it?
Will the work be done under containment with a HEPA air scrubber exhausting outdoors?
Which materials come out, and in what quantity?
How will you confirm the structure is dry before you leave?
What is the clearance method, who performs it, and is it in the price?
What is excluded from this estimate?
What warranty do you offer, for how long, and what voids it?
Can I have two references from similar jobs this year?

Every company you talk with is an independent business, and the ranges on this site are planning figures from published national data rather than quotes. Use them to read the estimates you receive, and let the answers to the questions above decide who gets the job. The red flags guide lists the answers that should end the conversation.