Negative Keywords for Contractors: Stop Wasting Google Ads Budget

What Negative Keywords Are and Why Contractors Need Them

Every time someone types a search into Google, your ad might show up. That is the point. But "might show up" is the problem. Google matches your keywords broadly by default. Bid on "plumber near me" and Google might also show your ad for "plumber salary near me," "how to be a plumber," or "plumber supply store." Every one of those clicks costs you money. None of them are homeowners looking to hire you.

Negative keywords fix this. They tell Google: "Never show my ad when this word is in the search." Add "salary" as a negative, and your ad stops appearing for plumber salary searches. Add "DIY" and you stop paying for people who want to fix it themselves.

Think of it this way. Your Google Ads budget is a bucket of water. Your negative keyword list is the plug at the bottom. Without the plug, money drains out on searches that will never become a phone call, a booked job, or a dollar of revenue.

How Much Money Are You Wasting Right Now?

I have audited hundreds of contractor Google Ads accounts. The pattern is the same almost every time. Between 20% and 40% of total ad spend goes to irrelevant clicks. On a $3,000/month budget, that is $600 to $1,200 per month. On a $5,000/month budget, $1,000 to $2,000.

That is not a rounding error. That is a crew member's weekly paycheck. Every single month.

Here are the categories of wasted spend I see most often:

Job seekers. "HVAC technician jobs," "plumber hiring near me," "electrician apprenticeship." These people want to work for you, not hire you. They click. You pay. They never call.

DIY searchers. "How to fix a leaky faucet," "AC not blowing cold air fix," "replace light switch yourself." These people are actively trying to avoid hiring a contractor. They click your ad looking for a video tutorial, not a phone number.

Students and researchers. "What does an electrician do," "plumbing code requirements," "HVAC certification." Academic searches. Zero commercial intent.

Wrong services. "Commercial HVAC contractor" when you only serve residential. "Pool plumbing" when you do not touch pools. "Solar panel electrician" when you are a residential wireman.

Supplier and wholesale searches. "Rheem furnace wholesale," "plumbing supply store," "electrical wire prices." These people want to buy parts, not hire labor.

Free and cheap seekers. "Free AC repair," "cheap plumber," "discount electrician." Some of these might become real leads, but most are price shoppers who will call 10 companies and pick the cheapest.

Every one of these clicks costs you real money. And every dollar you spend on them is a dollar that did not go toward the homeowner whose AC died in August and who needs someone there today.

Starter Negative Keyword Lists by Trade

Below are ready-to-use negative keyword lists organized by trade. Copy these into your Google Ads account as a starting point, then add to them as you review your search terms report each week.

Universal Negative Keywords (Add to Every Contractor Account)

These terms waste money regardless of your trade:

• job
• jobs
• hiring
• careers
• career
• salary
• salaries
• pay
• wage
• wages
• apprentice
• apprenticeship
• certification
• certified
• license
• licensing
• school
• schools
• training
• classes
• course
• courses
• degree
• college
• university
• exam
• test
• DIY
• yourself
• how to
• tutorial
• video
• youtube
• reddit
• free
• cheap
• cheapest
• wholesale
• supply
• supplies
• supplier
• parts
• part
• home depot
• lowes
• amazon
• ebay
• walmart
• menards
• complaints
• lawsuit
• scam
• fraud
• recall
• used
• rental
• rent
• manual
• diagram
• blueprint
• book
• books
• pdf
• definition
• wiki
• wikipedia

HVAC Negative Keywords

Add these on top of the universal list for HVAC campaigns:

• automotive
• auto
• car
• vehicle
• truck
• RV
• boat
• marine
• aircraft
• airplane
• portable
• window unit
• commercial (if residential only)
• industrial (if residential only)
• mini split DIY
• refrigerant price
• freon cost
• R-410A
• SEER rating chart
• BTU calculator
• HVAC design software
• solar powered
• geothermal
• swamp cooler
• evaporative cooler
• space heater
• pellet stove
• wood stove
• fireplace insert
• chimney sweep
• duct tape
• filter size
• filter subscription
• thermostat manual
• Nest setup
• Ecobee setup

Plumbing Negative Keywords

Add these on top of the universal list for plumbing campaigns:

• pool
• swimming pool
• spa
• fountain
• irrigation
• sprinkler
• fire sprinkler
• industrial (if residential only)
• commercial (if residential only)
• plumber's putty
• plumber's tape
• pipe wrench
• PVC pipe
• PEX tubing
• toilet seat
• faucet handle
• shower head
• showerhead
• plunger
• drain snake
• auger
• septic (if you do not service septic)
• well pump (if you do not service wells)
• sump pump DIY
• softener salt
• water filter
• flush kit
• gas line (if you do not do gas)
• medical
• dental
• veterinary

Electrical Negative Keywords

Add these on top of the universal list for electrical campaigns:

• automotive
• auto
• car
• vehicle
• guitar
• bass
• amp
• amplifier
• electric fence
• electric bike
• electric scooter
• electric car
• EV charger DIY
• electric blanket
• industrial (if residential only)
• commercial (if residential only)
• power company
• utility company
• electric bill
• electricity rate
• electricity cost
• solar panel
• solar installation (if you do not do solar)
• generator rental
• extension cord
• power strip
• surge protector
• light bulb
• LED bulb
• smart switch
• wire gauge chart
• multimeter
• circuit diagram
• wiring diagram
• NEC code

How to Find Wasted Spend in Your Account

The negative keyword lists above are a starting point. Your actual waste will be specific to your account, your market, and your keyword setup. Here is how to find it.

Step 1: Pull Your Search Terms Report

In Google Ads, go to Keywords > Search terms. Set the date range to the last 30 days. This report shows every actual search that triggered your ad. Not the keywords you bid on. The real words people typed into Google before clicking.

Sort by cost, highest to lowest. The top of this list is where your money goes. If any of those searches have nothing to do with hiring a contractor, you found a leak.

Step 2: Flag the Wasters

Scan the report for four types of waste:

1. Zero-intent searches. Job seekers, students, researchers. These will never become a call.

2. DIY searches. Anyone adding "how to," "fix myself," "DIY," "tutorial," or "video" to your keywords.

3. Wrong-service searches. Commercial when you are residential. Pool plumbing when you do not do pools. Solar when you do not do solar.

4. Low-value modifiers. "Free," "cheap," "discount." These callers rarely convert into booked jobs at full margin.

Step 3: Calculate the Damage

Add up the cost of every irrelevant search term. I have seen HVAC accounts where "HVAC jobs near me" alone consumed $400 in a single month. One plumbing account spent $280 on "plumber salary" variations over 90 days. One electrical account blew $350 on "electric car charger" searches when they did not even offer EV charger installation.

Add those numbers up. That is the money you get back by adding negative keywords.

Step 4: Block Them

For each irrelevant term, click the checkbox next to it in the search terms report and select "Add as negative keyword." Choose whether to add it at the campaign level or at the ad group level. Campaign level blocks the term across all ad groups in that campaign. Ad group level blocks it in just one.

As a rule, add universal waste terms (jobs, salary, DIY, free) at the account or campaign level. Add trade-specific terms at the campaign level. Add nuanced terms (like "commercial" when you serve some commercial clients but not through this campaign) at the ad group level.

How to Add Negative Keywords in Google Ads

There are three places to manage negative keywords. Each serves a different purpose.

Method 1: Negative Keyword Lists (Best for Contractors)

Go to Tools > Shared library > Negative keyword lists. Create a list called "Universal Negatives" and add all the universal terms from the starter list above. Then create trade-specific lists: "HVAC Negatives," "Plumbing Negatives," "Electrical Negatives."

Apply each list to the relevant campaigns. The advantage: when you discover a new waste term, you add it to the list once and it applies everywhere automatically. No need to add it to 5 separate campaigns one at a time.

According to Google's negative keywords documentation, negative keyword lists can hold up to 5,000 terms and can be shared across multiple campaigns.

Method 2: Campaign-Level Negatives

Go to your campaign, click Keywords > Negative keywords. Add terms that only apply to that specific campaign. For example, if you run separate campaigns for "AC Repair" and "Furnace Repair," you might add "furnace" as a negative in the AC campaign and "AC" as a negative in the furnace campaign. This prevents overlap and keeps each campaign focused.

Method 3: Ad Group-Level Negatives

This is the most granular option. Use it when you need fine control within a campaign. Example: your "Water Heater" campaign has ad groups for "tankless water heater" and "traditional water heater." Add "tankless" as a negative in the traditional ad group and "traditional" in the tankless ad group. This ensures each ad group only triggers for its specific service.

The Weekly Search Terms Review: Your Most Profitable 15 Minutes

Uploading a starter list on day one is essential. But the real ROI comes from checking your search terms report every week. New junk searches appear constantly. Google matches your keywords to searches you never imagined. The only way to catch them is to look.

Block 15 minutes every Monday morning. Open Google Ads. Pull the search terms report for the last 7 days. Sort by cost. Scan for anything irrelevant. Add negatives. Done.

This single habit will save most contractor accounts $300 to $800 per month. That is $3,600 to $9,600 per year. For 15 minutes of work per week.

If you are spending $3,000/month or more on Google Ads and you have never done this, I guarantee your first review will make you angry. You will see exactly where your money went. The good news: you can stop the bleeding in 15 minutes.

What a Real Cleanup Looks Like: Plumbing Company Case Study

A plumbing company in the Southeast was spending $3,200/month on Google Ads. Their cost per lead was $112. Industry benchmark for plumbing is $35 to $65. They knew something was wrong, but they could not figure out what.

We pulled their search terms report for the previous 90 days. Here is what we found:

• $680 spent on "plumber jobs near me," "plumbing careers," and "plumber apprenticeship" variations
• $420 spent on "how to fix a leaky faucet," "unclog drain DIY," and other tutorial searches
• $310 spent on "plumbing supply store," "PEX fittings," and "pipe wrench set"
• $190 spent on "free plumber," "cheap plumber near me," and "low cost plumbing"
• $140 spent on "commercial plumbing contractor" (they were residential only)

Total: $1,740 wasted over 90 days. That is $580 per month, or 18% of their entire budget, going to clicks that would never become a booked job.

We added 127 negative keywords in one session. Within 30 days:

• Cost per lead dropped from $112 to $68
• Monthly leads increased from 29 to 41 (same budget, better targeting)
• Booked jobs from Google Ads went from 10 to 16

Same $3,200/month budget. 60% more booked jobs. Nothing changed except removing the searches that should have never triggered their ads in the first place.

Common Negative Keyword Mistakes (and How to Avoid Them)

Mistake 1: Never Setting Them Up

This is the biggest one. Most contractor accounts I audit have zero negative keywords. The account was set up, keywords were added, and nobody ever checked what searches actually triggered the ads. Every irrelevant click from day one has been burning money.

Fix: Start with the lists in this article. Add them today. Then review weekly.

Mistake 2: Using Broad Match Without Negatives

Google's broad match keyword type casts the widest net. Bid on "AC repair" with broad match and Google might show your ad for "AC repair manual," "AC repair certification," or "AC repair tools." Broad match is powerful because it catches searches you did not think of. But without negative keywords, it catches everything you do not want, too.

If you are running broad match (and Google now defaults to it), your negative keyword list needs to be twice as long. The wider the match type, the more negatives you need.

Your Quality Score also suffers when irrelevant clicks drive down your click-through rate. People see your ad for a search that does not match. They skip it. Google records a non-click. Your expected CTR drops. Your Quality Score drops. Your CPC goes up. It is a downward spiral that starts with missing negative keywords.

Mistake 3: Blocking Too Aggressively

The opposite mistake. Adding "repair" as a negative when you offer repair services. Adding "near me" because one irrelevant search contained it. Adding "cost" or "price" when those searches actually indicate someone researching a purchase.

Before adding a negative keyword, ask: "Could a homeowner ready to hire me use this word?" If the answer is yes, do not add it.

Some terms that look like waste but are actually high-intent:

• "cost" and "price" (people researching a purchase)
• "best" (people comparing options, ready to choose)
• "reviews" (people validating before calling)
• "near me" (strong local intent)
• "emergency" (highest urgency, highest conversion)

Block the junk. Protect the intent.

Mistake 4: Adding Negatives and Never Reviewing

Your market changes. Google changes its matching behavior. New searches appear. A negative keyword you added 6 months ago might now block profitable traffic because Google expanded how it interprets your keywords.

Review your negative keyword lists quarterly. Check if any negatives are conflicting with your active keywords. Google Ads will flag these conflicts under Keywords > Search terms > Negative keywords with a "Conflicting" status.

Mistake 5: Only Using Account-Level Negatives

Account-level negatives block terms everywhere. That is right for "jobs" and "salary." But it is wrong for "commercial" if you have one campaign targeting commercial clients and another targeting residential. Or "tankless" if you have separate campaigns for tankless and traditional water heaters.

Use the right level. Account-level for universal junk. Campaign-level for campaign-specific terms. Ad group-level for granular control within campaigns.

Negative Keywords and Match Types: One Detail That Matters

Negative keywords have their own match types, and they work differently from regular keyword match types.

Negative broad match (default): blocks your ad when the search contains all the negative keyword terms in any order. Add "plumber jobs" as a negative broad match and it blocks "plumber jobs near me" and "jobs for plumber in Dallas." It will still show for just "plumber" or just "jobs" alone.

Negative phrase match: blocks when the search contains the exact phrase in that order. "Plumber jobs" blocks "plumber jobs near me" but NOT "jobs for plumber" (different word order).

Negative exact match: blocks only when the search matches the negative keyword exactly. [plumber jobs] only blocks the search "plumber jobs," not "plumber jobs near me."

For most contractor accounts, negative broad match is the right choice. It casts the widest blocking net. Use phrase match when you need more precision.

One important difference: negative keywords do not match close variants or synonyms. If you add "plumbing jobs" as a negative, it will not automatically block "plumber jobs." Add both variations manually.

Building a System That Keeps Your Budget Clean

Negative keyword management is not a one-time project. It is an ongoing system. Here is the process I use for every contractor client we manage.

Day 1: Load starter lists. Add the universal list and trade-specific list from this article. This immediately blocks the most common waste.

Week 1: First search terms review. Pull 30 days of data if available. Flag and block every irrelevant term. Expect to add 50 to 100 negatives on the first pass.

Weekly (every Monday): 15-minute review. Pull the last 7 days. Sort by cost. Add new negatives. This is the habit that protects your budget month after month.

Monthly: Performance check. Compare CPL before and after your negative keyword updates. Track the trend. Your CPL should drop or hold steady. If it rises, check for conflicting negatives or market shifts.

Quarterly: Full list audit. Review your entire negative keyword list. Remove anything that might now conflict with new campaigns or services you have added. Check for gaps in coverage.

This system takes less than an hour per month once it is running. The return: 20% to 40% of your budget redirected from waste to real leads. On a $3,000/month account, that is $7,200 to $14,400 per year in recovered spend.

If you are setting up your first plumbing Google Ads campaign, build your negative keyword lists before you turn on a single ad. Starting clean costs nothing. Cleaning up after months of waste costs everything those clicks already spent.

Your Google Ads account is only as good as the searches it refuses. The keywords you block matter just as much as the keywords you bid on. Build the list. Review it weekly. Keep your budget working on the homeowners who are ready to pick up the phone.

Frequently Asked Questions About Negative Keywords for Contractors

How many negative keywords should a contractor have in Google Ads?

Most contractor accounts need 100 to 300 negative keywords to block the majority of wasted spend. Start with 60 to 80 from a universal starter list, add 30 to 50 trade-specific terms, then build from there through weekly search terms reviews. Accounts running broad match keywords typically need more negatives because Google matches to a wider range of searches.

What is the difference between negative broad match and negative exact match?

Negative broad match blocks your ad whenever a search contains all the words in your negative keyword in any order. Negative exact match only blocks the search if it matches your negative keyword exactly, word for word. For contractors, negative broad match is usually the better choice because it catches more variations of irrelevant searches. Negative exact match is too narrow for most waste-blocking purposes.

How often should I check my Google Ads search terms report?

Weekly. Set aside 15 minutes every Monday to pull the last 7 days of search terms data, sort by cost, and add negatives for any irrelevant searches. This single habit saves most contractor accounts $300 to $800 per month. Skipping this review for even 30 days can let hundreds of dollars in wasted clicks accumulate before you catch them.

Can negative keywords hurt my Google Ads performance?

Yes, if you add them carelessly. Blocking terms like "cost," "price," "best," "near me," or "emergency" will cut off high-intent homeowners who are actively looking to hire. Before adding any negative, ask whether a ready-to-buy customer might use that word. Block junk searches (jobs, salary, DIY, free) aggressively. Protect buying-intent searches completely. Review your negative keyword list quarterly to catch conflicts with new campaigns.

What percentage of Google Ads budget do contractors waste without negative keywords?

Most contractor accounts without negative keywords waste 20% to 40% of their total ad spend on irrelevant clicks. On a $3,000/month budget, that is $600 to $1,200 per month going to job seekers, DIY searchers, students, and people looking for services you do not offer. That money generates zero calls, zero booked jobs, and zero revenue.