Data
Iowa contractor registrations
Last updated November 7, 2026
Next update December 2026
Iowa doesn’t license most building trades the way Oregon or Washington do. It registers them. Every contractor earning at least $2,000 a year from construction in the state must sign up with one office, and that office publishes the active list as one open file. We, TrustPast, downloaded it on 17 October 2026 and kept 18,096 registration records. They created 17,133 new companies in our database and matched 895 that were already there.
This page counts those 17,133 companies. By the activity each registered under, by trade, by how many registrations each holds, by when the registration runs out and by where the businesses are. Then it shows where our pipeline put them. One thing it can’t show is age, and the section on dates explains why.
What a registration is
The Department of Inspections, Appeals, and Licensing, DIAL for short, runs the register. Its page says: “Iowa law requires all individual and business construction contractors performing ‘construction’ work to be registered with the Department of Inspections, Appeals, and Licensing (DIAL) if they earn at least $2,000 a year from construction.” Below that line, or for work only on your own property, no registration is needed.
DIAL gives four reasons for the register: compliance with unemployment insurance laws, compliance with workers’ compensation laws, collecting payments owed by out-of-state contractors, and making “information about contractors available to the general public.” So it is a tax and insurance register first. It doesn’t test anyone’s skill.
The net is wide. DIAL’s words: “The definition of construction is very broad. Carpenters, electricians, plumbers, roofers, painters and many others must register.” Subcontractors aren’t covered by the general contractor’s registration and register on their own. A firm with two businesses under two federal identification numbers registers each one.
The terms DIAL publishes:
| Rule | What DIAL says |
|---|---|
| Who | Individuals and businesses earning at least $2,000 a year from construction in Iowa |
| Fee | “There is a $50 application fee.” |
| Term | “Your registration must be renewed every year.” |
| Renewal notice | “The month before your registration expires, a renewal form will be sent by mail or email.” |
| Number | Kept on an on-time renewal; a sole proprietor that incorporates re-applies and gets a new one |
| Unemployment insurance | An Iowa unemployment insurance number, in-state or out-of-state, “even with no employees” |
| Bond | $25,000 for most contractors based outside Iowa; with employees, a workers’ compensation certificate and a $25,000 bond |
| Plumbing and mechanical | A joint application “for a 3-year registration and contractor license” with the Plumbing & Mechanical Systems Board |
The last row matters for the tables below. A plumbing, HVAC, refrigeration, sheet metal or hydronic firm gets its registration together with its board licence, on a three-year term. Everyone else renews yearly. A registration is the floor, not a trade licence: an electrician or plumber may hold a board licence as well, which isn’t in this file.
The file we read
DIAL publishes the register on the Iowa Data Hub as dataset 1052, “Active Iowa Construction Contractor Registrations”. Its description: “This list provides data on all individual contractors and businesses performing ‘Construction’ work within Iowa who have active registrations.” The page gives a weekly update frequency and a CC BY licence. On 7 November it gave a last update of 3 November 2026 and 18,257 rows.
The page also publishes the filter behind the file: rows whose status is “REGISTERED” and whose expiry date hasn’t passed. So the file is a snapshot of who is registered today. A firm that let its registration lapse simply drops out.
Our collector downloaded the file once. The 18,096 records went into the database between 13:32:54 and 13:33:06 UTC on 17 October 2026. They sit on 18,028 companies. 17,133 were new, created by this file, and hold 17,197 of the records. The other 895 were already in our database from another file, and hold the other 899. 562 of them came from Virginia’s licence file, 138 from Florida’s, 113 from Texas’s, 57 from New York City’s buildings department, 12 from California’s licence board, 9 from the federal movers register and fewer than five from other files. From here on, the tables count the 17,133 companies the Iowa file created.
Which activity they registered under
Each row names one primary activity, taken from the North American Industry Classification System’s construction codes. The Data Hub page lists 32 of them. All 32 appear here.
| Primary activity | Trade we gave it | Companies | Share |
|---|---|---|---|
| Residential Remodelers | General | 3,380 | 19.7% |
| All Other Specialty Trade Contractors | General | 1,696 | 9.9% |
| Electrical and Wiring Installation | Electrical | 1,619 | 9.4% |
| Plumbing/Heating & A/C Contractors | Plumbing | 1,430 | 8.3% |
| Other/Undefined | General | 1,288 | 7.5% |
| Commercial & Institutional Bldg Construction | General | 902 | 5.3% |
| Roofing Contractors | Roofing | 834 | 4.9% |
| Finish Carpentry Contractors | General | 800 | 4.7% |
| New Single-Family Housing Construction | General | 735 | 4.3% |
| Site Preparation Contractors | General | 610 | 3.6% |
| Painting & Wall Covering Contractors | General | 466 | 2.7% |
| Poured Concrete Foundation Contractors | General | 336 | 2.0% |
| Flooring Contractors | General | 302 | 1.8% |
| Drywall & Insulation Contractors | General | 282 | 1.6% |
| Masonry Contractors | General | 279 | 1.6% |
| Other Foundation/Structure & Bldg Exterior | General | 279 | 1.6% |
| Framing Contractors | General | 240 | 1.4% |
| Highway/Street and Bridge Construction | General | 228 | 1.3% |
| Water/Sewer Line Construction | General | 216 | 1.3% |
| Siding Contractors | General | 193 | 1.1% |
| Power/Communication Line Construction | General | 190 | 1.1% |
| Other Building Finishing Contractors | General | 139 | 0.8% |
| New Housing For-Sale Builders | General | 103 | 0.6% |
| Other Building Equipment Contractors | General | 102 | 0.6% |
| Industrial Building Construction | General | 85 | 0.5% |
| Structural Steel/Precast Concrete Contractors | General | 81 | 0.5% |
| Other Heavy/Civil Engineering | General | 80 | 0.5% |
| Glass and Glazing Contractors | General | 73 | 0.4% |
| New Multifamily Housing Construction | General | 63 | 0.4% |
| Tile/Terrazzo Contractors | General | 49 | 0.3% |
| Oil/Gas Pipeline Construction | General | 29 | 0.2% |
| Land Subdivision | General | 24 | 0.1% |
| All | 17,133 | 100% |
Remodelers lead by a distance: one company in five. The “Other/Undefined” row is 1,288 firms whose activity DIAL files under the bare construction code, 230000.
Our collector gives three activities a trade of their own. Everything else is filed as general construction.
| Trade | Companies | Share |
|---|---|---|
| General | 13,250 | 77.3% |
| Electrical | 1,619 | 9.4% |
| Plumbing | 1,430 | 8.3% |
| Roofing | 834 | 4.9% |
| All | 17,133 | 100% |
The plumbing row is DIAL’s “Plumbing/Heating & A/C Contractors”. The file uses one activity for plumbing, heating and air conditioning, so this page can’t split plumbers from HVAC firms. The trade is the activity the firm chose on its form, not a licence. A remodeler that does its own wiring is counted as general.
How many registrations a company holds
Most firms hold one. DIAL asks for a separate registration only for a separate business with its own federal identification number.
| Registrations per company | Companies | Registration records |
|---|---|---|
| 1 | 17,069 | 17,069 |
| 2 | 64 | 128 |
| All | 17,133 | 17,197 |
17,069 companies, 99.6%, hold one registration. 64, 0.4%, hold two. That is far below the share on licence files that issue one licence per trade, such as Oregon’s trade contractor licences, where 11.9% hold two or more. A registration covers the business, not each kind of work.
When the registrations run out
The file lists active registrations only. So the expiry date is the next renewal, not a record of lapses.
| Expires | Companies | Share |
|---|---|---|
| October 2026 | 378 | 2.2% |
| November 2026 | 649 | 3.8% |
| December 2026 | 910 | 5.3% |
| January to June 2027 | 8,940 | 52.2% |
| July to December 2027 | 4,809 | 28.1% |
| During 2028 | 17 | 0.1% |
| June 2029 | 1,430 | 8.3% |
| All | 17,133 | 100% |
The yearly term shows. 15,686 companies, 91.6%, renew between October 2026 and the end of 2027. Unlike a licence type that renews all at once, Iowa’s dates spread through the year: each firm’s renewal falls a year after its last one. The busiest months in 2027 are March, with 1,607, and April, with 1,626.
The June 2029 row is the joint plumbing and mechanical registration. 1,428 of the 1,430 plumbing, heating and air conditioning firms expire on 30 June 2029, which matches the three-year term DIAL gives the joint application. The other two plumbing firms expire in 2027, and two general firms in 2029.
The 378 October 2026 registrations were active when we downloaded the file on 17 October. Some will have renewed since and some won’t. This page can’t tell which.
Why there is no age table
The file has an issue date, but it is the issue date of the current term. Each renewal resets it. On the companies this file created, the year of that date reads:
| Current term issued | Companies |
|---|---|
| 2026 | 14,910 |
| 2025 | 2,222 |
| Earlier | 1 |
| All | 17,133 |
A remodeler registered since the 1990s and one registered last spring both show 2025 or 2026. So our collector writes the date into a note and leaves the company’s first-registration date empty, rather than understate its age. For the age of trade firms from files that do carry an original date, see our table of how long trade licences have been held.
The register adds one more limit. DIAL says a sole proprietor that incorporates must “re-apply as a new business and be issued a new contractor registration number.” So even the number can be younger than the firm behind it.
Where the businesses are
The file gives the address on the registration. 13,973 companies, 81.6%, give one in Iowa.
| State of the address | Companies |
|---|---|
| Iowa | 13,973 |
| Nebraska | 875 |
| Minnesota | 481 |
| Illinois | 389 |
| Wisconsin | 227 |
| Missouri | 190 |
| South Dakota | 174 |
| Texas | 115 |
| Kansas | 85 |
| Ohio | 52 |
| 35 other states | 554 |
| No state given | 18 |
| All | 17,133 |
All six neighbours come next, with Nebraska first. That fits the register’s purpose: DIAL wants the bond and the unemployment number from out-of-state firms that work in Iowa. Roofers are the most likely to give an address outside Iowa. 260 of 834 roofing firms, 31.2%, give an address outside Iowa or none. Electrical firms follow at 326 of 1,619, 20.1%, and general firms at 2,395 of 13,250, 18.1%. The plumbing and HVAC firms, on their joint board registration, are the most local: 179 of 1,430, 12.5%. Our page for roofing companies covers the records a roofing firm keeps, wherever it is based.
The file also names the county. The Iowa addresses carry 99 county names; 293 carry none.
| County | Companies | Share of Iowa addresses |
|---|---|---|
| Polk | 2,431 | 17.4% |
| Linn | 1,071 | 7.7% |
| Johnson | 548 | 3.9% |
| Scott | 496 | 3.5% |
| Dallas | 418 | 3.0% |
| Dubuque | 408 | 2.9% |
| Black Hawk | 397 | 2.8% |
| Warren | 378 | 2.7% |
| Woodbury | 366 | 2.6% |
| Story | 363 | 2.6% |
| Pottawattamie | 330 | 2.4% |
| Muscatine | 164 | 1.2% |
| Sioux | 161 | 1.2% |
| Webster | 159 | 1.1% |
| Buchanan | 150 | 1.1% |
| 84 other names | 5,840 | 41.8% |
| No county | 293 | 2.1% |
| All in Iowa | 13,973 | 100% |
The fifteen named counties hold 7,840 companies, 56.1%. Polk, around Des Moines, has one Iowa firm in six, and Dallas and Warren, beside it, add 796 more. One name is left in the “other” row on purpose. 284 rows give “Iowa” as the county. Iowa has an Iowa County, but those rows include towns well outside it, so the field there may hold the state. We don’t count it as a county.
The cities, as written on the address, name 924 places.
| City | Companies |
|---|---|
| Des Moines | 1,030 |
| Cedar Rapids | 615 |
| Sioux City | 307 |
| Ankeny | 299 |
| Davenport | 266 |
| Dubuque | 253 |
| West Des Moines | 238 |
| Urbandale | 237 |
| Council Bluffs | 227 |
| Waterloo | 223 |
| 914 other names | 10,278 |
| All in Iowa | 13,973 |
Iowa City ties Waterloo at 223 and sits in the other names. The ten largest hold 3,695 companies, 26.4% of the Iowa addresses. Des Moines alone has 1,030, 7.4%. Nearly three in four Iowa contractors give a town outside the top ten. This is the town on the address, not where the work is done.
What our pipeline did with them
Our pipeline puts every company in one lane, by headcount. Lane C is every company under 30 people or with no headcount on record, and Polyshares is its buyer. The Iowa file carries no headcount, so the companies started in lane C.
| Lane and status | Companies |
|---|---|
| Lane C, qualified | 11,796 |
| Lane C, marked contacted | 5,294 |
| Lane C, held for review | 36 |
| Lane B | 5 |
| Excluded | fewer than five |
| All | 17,133 |
11,796 companies, 68.8%, sit in lane C as qualified. 5,294, 30.9%, are marked contacted: they went into our email outreach, which ran from 16 October to 5 November 2026 and has stopped. 36 are held for review, where a person clears them or they stay out. Five sit in lane B, which isn’t Polyshares’ lane.
What a registration says about the record
A registration says a firm is on the books for unemployment insurance and, with employees, carries workers’ compensation. A firm based outside Iowa files a bond too. It says nothing about the files behind the work. A remodeler renewed for 2027 could sit on twenty years of job folders, or on last spring’s first invoice.
What Polyshares looks at is the record itself. Its home page says: “The length and texture of the record matter more than headcount or revenue.” Under “Who qualifies” it puts “Any company with real operating history, in any sector,” and construction is among the sectors it names. On price: “Depth of operating history and how much visible reasoning the record contains move the number far more than raw volume does.”
Polyshares publishes a few of its deals. Polyshares lists a roofing company, filed under home services, at $450,000 (indicative, not an offer). Polyshares lists a general contractor, filed under construction, at $300,000 (indicative, not an offer). Each is a “Perpetual exclusive license to the operational record,” “Anonymized before delivery.” A published deal is one company’s price. It doesn’t predict anyone else’s.
What this means for an Iowa contractor
The records that count are the ones that show how a job was worked out. The register can’t say how long you’ve kept them. You can.
For a remodeler, the largest group here, that’s the walkthrough notes, the estimates, the selections sheets, the change orders and the punch lists. A kitchen job where the wall turned out to hold a beam, with the revised bid and the client’s sign-off, is the kind of record that shows reasoning.
For a roofer, it’s the inspection photos, the measurements, the insurance supplements and the warranty files. A hail season’s worth of claims, with what the adjuster first approved and what the supplement added, carries a lot.
For an electrician, it’s the bids, the permits, the load calculations and the inspection corrections. For a plumbing or HVAC firm, it’s the service tickets, the camera reports, the start-up sheets and the maintenance history of each system. A no-heat call in a Dubuque January, what was measured and what the callback fixed, is worth keeping. Our page for plumbing companies goes file by file.
For all of them, the estimates and the change orders carry the most. Our page on estimates and quotes covers the bids that became jobs and the ones that didn’t, and our page on job files and work orders covers what happened after the yes. Polyshares counts “spreadsheets, CRM history, support tickets” and “accounting and ERP exports” as operational data.
Before any of it is used, it’s de-identified. Polyshares says identifying fields are stripped by a specialist partner “before anything moves.” Customer names and payments are never what is wanted. What is wanted is how the work was done: how an estimate became a job, how a change order was settled, how a fault was traced. Our explainer on what data buyers actually want from a trade business puts those records in order, and how de-identification works shows what gets removed.
How many years of yours can you still open? Our estimate takes two minutes and asks exactly that.
What the tables do not prove
The file is a snapshot of active registrations. It says nothing about how long a firm has been registered, and nothing about firms that have stopped.
The trade is the primary activity the firm chose, read by our collector. A firm registered as a remodeler may do mostly roofing. Plumbers and HVAC firms share one activity and can’t be told apart here.
A registration isn’t a licence. Plumbing and mechanical firms hold a Plumbing & Mechanical Systems Board licence beside it, and no board’s licence file is counted here. Firms earning under $2,000 a year from construction don’t register at all.
Our matching keeps one company per business name, state and town. A firm that trades under two names stays two companies. Two firms with the same name in the same town would become one.
Our lane is the pipeline’s reading of the records we hold, not a buyer’s decision. Polyshares decides on its own review; it says “We read a sample of the record.”
What is never included
This page holds counts only. It names no company and shows no registration number, address, phone number, email address or person. Every company here was created from a business name on the row; the registrant’s own name is in the file, and we keep the person out of every table.
In a licence of records, the customer’s own information stays out. Polyshares says its licence “does not cover what you hold on behalf of your own clients.” It says identifying fields, customer names, emails and account numbers are “stripped by a specialist PII partner before Polyshares or any lab sees the record.” Our advice: payment card numbers, bank statements and payroll should never be in an export at all. Nor should a home’s door codes or the alarm details on a job ticket. How it’s safe walks through what leaves your systems, and when.
For the same kind of count in other states, see Oregon trade contractor licences, Minnesota trade contractor licences and licensed trade contractors by state board.
Questions and answers
Does this page show how old Iowa contractors are? No. The file’s issue date is that of the current term, and every renewal resets it. 17,132 of the 17,133 companies show a 2025 or 2026 date.
Is an Iowa registration a trade licence? No. DIAL registers every contractor earning at least $2,000 a year from construction, whatever the trade. It’s a register for unemployment insurance, workers’ compensation and out-of-state bonds.
Why do the plumbers expire in 2029? Plumbing, HVAC and other mechanical firms register through a joint application with the Plumbing & Mechanical Systems Board, which DIAL describes as a three-year registration and contractor licence.
Does an Iowa registration qualify a firm with Polyshares? Not by itself. Polyshares prices the record, not the registration: “We read a sample of the record. That is how we price it”.
Methodology
The file. “Active Iowa Construction Contractor Registrations” on the Iowa Data Hub (dataset 1052), published by the Iowa Department of Inspections, Appeals, and Licensing under a CC BY licence. One row per active registration, with the registration number, the registrant’s first and last name, the business name, address, city, state, ZIP code, county, issue date, expiry date and primary activity; the file we downloaded on 17 October also carried an email and a phone column. The page’s metadata gives a weekly update frequency, a filter of status “REGISTERED” and an expiry date not yet passed, a last update of 3 November 2026, and 18,257 rows.
What was collected. Our collector (ia-dial) downloaded the zipped file once. A row naming neither a business nor a person is skipped. Where a row has no business name, the registrant’s own name is the business. The trade comes from the primary activity: “Roofing Contractors” is roofing, “Plumbing/Heating & A/C Contractors” is plumbing, “Electrical and Wiring Installation” is electrical, and every other activity is general. Rows are written with the three trade activities first and general last, and a company keeps the trade and activity of its first row. The issue date goes into a note as the current term’s date, and the first-registration date stays empty. The run of 17 October 2026 wrote 18,096 records between 13:32:54 and 13:33:06 UTC.
Status. The file lists active registrations only. The collector marks a company active unless its expiry date has passed.
When we read it. We read the host database read-only on 7 November 2026 through single read-only statements, counts only. The Data Hub page and its metadata, DIAL’s contractor registration page, and the Polyshares pages were fetched the same day.
Which companies. The tables count the 17,133 companies whose source is ia-dial, the ones this file created. The 895 that another file created first are left out. Registrations per company count every ia-dial record linked to the company. A record matches a company by business name, state and town.
The queries, in plain words. Records, companies and fetch times for the source; companies by first source for those another file created; companies by primary activity and trade; records per company; companies by expiry month, and by trade and expiry year; companies by the year in the current-term note; lane and pipeline status; companies by state, and by trade inside and outside Iowa; Iowa companies by county from the collector’s note, the count of county names and of rows without one, and the towns on the rows that give “Iowa” as the county; Iowa companies by city in capitals, and the count of distinct cities. Each statement and its output are kept with the page’s working files for a reviewer to re-run.
Places. The state, county and city are the address’s. County and city names are counted in capitals as written. The county and city tables count Iowa addresses only. The rows that give “Iowa” as the county are counted in the “other names” row.
Suppression. Any cell under five is merged or marked: the other files that created a company first, the current terms issued before 2025, the excluded companies.
Lane and status. The pipeline’s own at the read, set by our qualification step.
Left out. The licence files of Iowa’s trade boards; the registrations that lapsed before 17 October 2026; registrations made since; the 895 companies another file created first. The issue date is the current term’s, so there is no age table.
Refresh. The tables are rebuilt monthly from a fresh download and a new read of the database. The next update is due 7 December 2026.
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Sources
- Iowa Data Hub, Active Iowa Construction Contractor Registrations (dataset 1052): the file, its columns, who must register, the primary activities, CC BY, weekly updates
- Iowa Department of Inspections, Appeals, and Licensing, Contractor Registration: who must register, the $50 fee, the yearly renewal, the bond, the joint three-year registration for plumbing and mechanical firms
- Polyshares, home page: who qualifies, the length and texture of the record, anonymisation, what the licence does not cover (polyshares.com)
- Polyshares, case studies: a roofing company and a general contractor, with their published deal amounts (polyshares.com)