A negative keyword list is institutional knowledge about what doesn’t work for your business. The longer you manage an account without building one, the more money you’re leaving on the table.
Every Google Ads account I audit that hasn’t been actively managed has the same problem: money going to irrelevant queries because nobody has been adding negatives. Sometimes 30-40% of spend.
What Are Negative Keywords in Google Ads?
Negative keywords tell Google which searches should NOT trigger your ads. If you’re a personal injury attorney and you add ‘personal injury settlement calculator’ as a negative keyword, people searching that query won’t see your ads.
Without negatives, Google’s matching algorithms will broaden your reach in ways that generate clicks from people who will never buy from you.
Why Are Negative Keywords So Important?
Every dollar spent on an irrelevant click is a dollar that can’t go toward a potential customer. And it’s not just the direct cost — irrelevant clicks lower your CTR, which can lower your Quality Score, which increases your CPC across the board.
Negative keywords are one of the few things in Google Ads that compound. Every negative you add prevents future waste on that query, forever, at no additional cost.
What Negative Keywords Should You Add First?
Information vs. transaction intent. Someone searching ‘how to fix a leaky faucet’ doesn’t want to hire a plumber — they want to do it themselves. Add ‘how to,’ ‘DIY,’ ‘yourself,’ ‘tutorial,’ ‘guide’ as negatives for most service businesses.
Job seekers. ‘Jobs,’ ‘career,’ ‘hiring,’ ‘salary,’ ‘employment’ — these queries come from people looking for work, not services.
Competitors’ exact brand names (unless you’re intentionally bidding on competitor terms).
Irrelevant industry terms. A commercial plumber should add ‘residential’ as a negative. A roofing company that doesn’t do repairs should add ‘DIY roof repair.’
Cheap/free modifiers. ‘Free,’ ‘cheap,’ ‘low cost,’ ‘budget’ — unless you’re specifically targeting price-conscious buyers, these modifiers often produce lower-quality leads.
How Do You Find the Right Negative Keywords?
The search terms report is your primary source. Go to Keywords → Search terms. Sort by cost. Read every query that your ads triggered. Any query that wouldn’t produce a qualified customer becomes a negative.
Do this weekly for the first 90 days of a campaign. Monthly after that.
Also think proactively before launch. Brainstorm all the ways someone could search for adjacent things that aren’t your service. Add those as campaign-level negatives from day one — you’ll waste less money in the learning phase.
What’s the Difference Between Campaign-Level and Ad Group-Level Negatives?
Campaign-level negatives apply to all ad groups in that campaign. Use for things that should never trigger ads across your whole campaign — job terms, informational queries, irrelevant industries.
Ad group-level negatives apply only to specific ad groups. Use for preventing cross-contamination between ad groups. If you have one ad group for ‘plumbing repair’ and another for ‘drain cleaning,’ add the drain cleaning terms as negatives in the plumbing ad group and vice versa — so the right ad group always captures the right query.
How Big Should Your Negative Keyword List Be?
There’s no target number. But a well-managed account that’s been running for a year should have hundreds of negatives at minimum.
The businesses I’ve taken over with the most efficient accounts almost always have the largest negative keyword lists. That correlation isn’t a coincidence.