Negative keywords: stop paying for the wrong clicks

Negative keywords tell Google Ads which searches should never show your ad. If you repair roofs and someone types "roofing jobs near me" or "how to patch a roof leak yourself," a negative keyword stops you paying for that click. It is the single cheapest way to cut wasted spend, and most small accounts either have no negative list or one that was set up once and forgotten.

This guide covers how negative match types behave (they work differently from normal keywords), which categories to add on day one, how to build and maintain lists, and the mistakes that block good customers by accident.

How negative keywords match

Here is the catch most people miss: negative keywords do not expand to close variants, misspellings or synonyms the way positive keywords do. If you add "free" as a negative, Google won't automatically block "freebie." You have to think of the variants yourself.

For most day-to-day blocking, a single-word broad negative ("jobs," "salary," "diy") is the workhorse. Phrase and exact negatives are for surgical cases, where one word is fine in some contexts and not in others.

Categories to block on day one

You don't need to wait for search data to start. For most local service businesses, these groups are safe to add before launch, after a quick sanity check against what you actually sell:

• Jobs and careers: jobs, hiring, career, salary, apprenticeship, resume, internship, indeed, glassdoor
• Learning and DIY: how to, diy, tutorial, course, training, certification, school, youtube, manual
• Free and very cheap: free, cheapest, used, second hand (careful if you sell used goods)
• Research rather than buying: definition, meaning, wiki, reddit, pdf, examples
• Parts and supplies for do-it-yourselfers: parts, wholesale, supply, home depot, lowes (adjust to your trade)
• Services you don't offer: if you're a residential cleaner and don't do commercial or carpet, add those terms
• Areas you don't serve: names of distant cities and states that show up in searches

One caution on the "learning" group: if you run a training business, a driving school or a course, words like "course" and "lessons" are your customers. Every list needs a sense check.

Building your list from real data

After the first week, the search terms report becomes your main source. Open it, sort by cost, and read every line that has spent money. For each irrelevant term, ask which word makes it irrelevant, and add that word, not the whole search. Blocking "water heater repair jobs" only stops that exact idea; blocking "jobs" stops hundreds of variants.

Do this weekly for the first couple of months, then every two weeks. A new account usually needs heavy pruning early on, and then the list stabilizes. Accounts that use broad match keywords need more frequent reviews, because broad match keeps discovering new search patterns.

Also scan the terms that did not spend much yet. A handful of impressions on "plumber salary Texas" today is a costly click next month.

A quick example

Imagine a garage door company in a suburban county. After two weeks, its search terms report shows clicks from "garage door opener manual," "garage door spring replacement cost diy," "garage door installer jobs" and "garage door repair" plus a city 200 miles away. Four negatives fix all of it: manual, diy, jobs and that city's name. Notice what stays: "garage door spring replacement cost" without "diy" is often a real buyer comparing prices, so it keeps running.

Lists, levels and structure

Negative keywords can sit at three levels:

• Ad group level: to steer searches between ad groups. If "drain cleaning" and "sewer line replacement" are separate ad groups, add "sewer" as a negative in the drain group so each search reaches the right ad.
• Campaign level: for terms that are wrong for one campaign but fine for another.
• Shared negative keyword lists: created once in the shared library and applied to many campaigns. Ideal for the universal blocks like jobs and DIY.

I usually keep three shared lists in a small account: universal (jobs, DIY, free), geography (areas outside the service zone) and competitors, if the owner prefers not to appear for competitor names. Then campaign-level negatives handle the specifics.

Performance Max and some other automated campaign types have historically limited where negatives can be added. Google has been expanding the options, including campaign-level negatives for Performance Max, so check what your account allows. My piece on Performance Max on a small budget has more on that.

Mistakes that cost you customers

Negatives can do damage too. I've seen accounts where a single word blocked half the good traffic:

• Blocking a word that is part of your service. A locksmith adding "car" because of car dealership searches also blocks "car lockout."
• Conflicts with your own keywords. Google shows a warning when a negative blocks one of your active keywords. Read those warnings.
• Blocking "near me" or the city name by accident while trying to remove one specific search.
• Copying a generic list from the internet without reading it. Lists built for one industry often contain words that are gold for another.
• Going too narrow. If you block everything except exact phrases, the account stops finding new customers. Some exploration is healthy.

How negatives fit into the bigger picture

Negative keywords reduce waste, but they don't fix a weak offer, a slow landing page or a broken phone line. Think of them as one tool alongside clear ad groups, precise match types and solid conversion tracking. My list of 12 places where Google Ads wastes money shows where they sit among other leaks, and the article on cost per click explains why cutting irrelevant clicks also helps your average cost.

Weekly search term reviews and negative keyword maintenance are part of every Google Ads management plan I run, from $1,000/month. If you only want a starting list built for your business, an hour of consulting at $65 is often enough to get one in place and show you how to maintain it.