The Negative Keyword List Every Contractor Needs in Google Ads
A contractor spending $2,000 per month on Google Ads without a negative keyword list is handing 20 to 40 percent of that budget to people who will never call them. Job seekers clicking on plumbing ads because they want to become a plumber. Homeowners looking for DIY tutorials on water heater replacement. Students researching HVAC certification programs. Everyone except the person with a broken AC and a credit card.
Negative keywords block your ads from showing on searches that will never convert. They cost nothing to add and require no change to your bidding strategy or campaign structure. They are the single fastest way to improve what a dollar of ad spend produces, and most contractor Google Ads accounts go months or years without a real negative keyword list in place.
Read Your Search Terms Report First
Before adding any negative keywords, open your Search Terms report. In Google Ads, click Campaigns in the left menu, then select Search Terms under the Insights and Reports section. This report shows every actual search that triggered your ad and resulted in a click over the selected time period. Set the date range to the last 90 days.
Sort by spend, highest first. What you find in the top 20 to 30 rows is where your budget actually went. Most accounts running for more than a few months without maintenance will show searches like "how to fix my water heater," "HVAC technician salary," "plumbing supply house near me," and "HVAC school near me" somewhere in the high-spend rows. Each of those is a click you paid for that had zero chance of becoming a booked job.
Download the report as a CSV. You will use it to identify which of the six categories below are already costing you money, and which specific keywords to add immediately.
The Six Negative Keyword Categories
1. Job Seekers
Broad match keywords like "plumber," "HVAC technician," and "electrician" pull in every search containing those words, including searches by people looking for employment. A homeowner searches "emergency plumber near me." A job seeker searches "plumber jobs near me." Both clicks cost the same. Only one of them calls to book a service.
Add these as negatives in every home service campaign:
- jobs
- job
- hiring
- career
- careers
- salary
- employment
- apply
- apprentice
- apprenticeship
- openings
- resume
2. DIY and How-To Searches
Homeowners who want to fix something themselves are not calling a contractor. When they type their problem into Google, broad match shows your ad and they click it looking for instructions. You pay for the click. They realize it is not a tutorial and leave without calling.
- how to
- how do i
- DIY
- do it yourself
- tutorial
- step by step
- fix it myself
- instructions
- guide
- manual
3. Free and Low-Cost Intent
A homeowner searching for "free HVAC inspection" or "cheap plumber no service fee" has a price expectation that professional rates will not meet. Even if they call, the conversion rate from these leads is low and the review risk is high when the invoice surprises them.
- free
- cheap
- cheapest
- low cost
- no charge
- no fee
- discount
- budget
Note: "Affordable" is a judgment call. Some contractors market specifically to price-sensitive homeowners and want those clicks. Evaluate based on your own positioning before blocking it.
4. Wholesale, Parts, and Supply
Searches for parts and equipment attract other contractors buying wholesale, property managers sourcing materials, and homeowners trying to self-source parts for a DIY fix. None of them want to hire you for a service call. HVAC, plumbing, and electrical campaigns that run without these negatives frequently pull in searches from people buying compressors, PVC fittings, and circuit breakers in bulk.
- parts
- part
- wholesale
- supply
- supplies
- supplier
- wholesale price
- buy
- purchase
- for sale
5. Education and Certification
HVAC and electrical campaigns especially attract searches from students entering the trade. "HVAC near me" and "electrician near me" pull in "HVAC school near me" and "electrician certification near me" via broad match. These clicks cost the same as a service lead and convert at zero.
- school
- training
- certification
- certificate
- class
- course
- degree
- program
- license exam
- become a
- how to become
6. Wrong Service Type or Scope
General campaigns for "plumbing" or "HVAC" capture service types you may not offer. A residential plumber without commercial accounts does not want clicks from "commercial plumbing contractor." An HVAC company that does not service commercial refrigeration does not want clicks from "walk-in cooler repair." Add the service types outside your scope as negatives before they burn through budget.
Common examples by trade:
- HVAC: refrigeration, walk-in cooler, cold storage, commercial kitchen
- Plumbing: industrial, municipal, sewage treatment, septic design
- Electrical: high voltage, power plant, industrial, substation
- Roofing: commercial flat roof (if residential only), metal building
Account-Level vs. Campaign-Level Negatives
Google Ads has two places to add negative keywords: at the campaign level, and at the account level via a Negative Keyword List. Use both.
Job seeker terms, DIY terms, education terms, and parts terms almost never convert for any home service campaign. Add these at the account level by creating a Negative Keyword List under Tools and Settings, then applying it to all campaigns at once. One list, updated once, applies everywhere immediately.
Wrong-service terms are trade-specific. Add those at the campaign level so a plumbing campaign blocks commercial sewage terms while an HVAC campaign blocks refrigeration terms, without one blocking the other.
| Category | Where to Add | Match Type |
|---|---|---|
| Job seeker terms | Account-level list | Broad |
| DIY and how-to | Account-level list | Broad |
| Education and certification | Account-level list | Broad |
| Parts and wholesale | Account-level list | Broad |
| Free and cheap | Campaign level | Broad or Exact |
| Wrong service type | Campaign level | Broad |
The Weekly Search Terms Habit
Negative keywords are not a one-time setup. Google's broad match continuously expands which searches your ads appear for as campaigns age and Google finds new audiences to test. A term you blocked last month will not catch a variation Google starts matching next month.
Spend 15 minutes every week in the Search Terms report. Sort by impressions, not spend, to catch low-click queries before they accumulate cost. Any search without clear commercial intent (someone ready to hire a contractor right now) gets added as a negative. This habit keeps your campaigns lean and prevents your cost per lead from creeping up month over month as wasted spend compounds.
At 90 days, contractors who maintain this weekly habit consistently report 20 to 35 percent lower cost per lead compared to their first month, without any increase in budget. The budget did not change. The share of it reaching actual buyers did.
Three Actions This Week
- Pull your Search Terms report for the last 90 days. Sort by spend. Write down every search that would never end in a call to your business. Group them by the six categories above. These are your priority negatives: they have already cost you money, and adding them now stops the ongoing waste.
- Create an account-level Negative Keyword List. In Google Ads, go to Tools and Settings, then Negative Keyword Lists under Shared Library. Create a list called "Universal Negatives" and add every job seeker, DIY, education, and parts term from the list above plus the specific terms you found in your search terms report. Apply the list to every active campaign in your account.
- Block 15 minutes every Friday to review search terms. One weekly sweep catches new wasted clicks before they accumulate. Sort by impressions, not spend, and add anything without purchase intent as a broad negative. The contractors outperforming their budgets in 2026 are not spending more than their competitors. They are spending the same amount on a narrower set of searches where actual buyers are looking for a contractor to hire.