Most underperforming accounts we audit are not short of keywords. They are short of negative keywords.
You check the account and the budget has gone. The clicks are there. The enquiries are not. Somewhere in that spend are searches you would never have paid for if asked: courses, salaries, DIY guides, free templates, a competitor's brand name, somebody three counties away.
The usual fix is to paste in a list of negative keywords found online. That fix is worse than it looks. It blocks people who were about to buy, while the searches draining your budget keep running, because they are specific to your business and no generic list could know about them. If you've ever wondered whether Google Ads is still worth it for small businesses, wasted spend like this is usually the real answer.
This article covers how negative keywords work, including the part Google documents and almost nobody repeats, and how to decide what to block, keep, or split out in your own search terms report.
Key Takeaways
- A negative keyword stops your ad showing for a specific search. It does not lower your bid. It is a hard block.
- Negative keywords do not expand to close variants. Block "flowers" and your ad still shows for "red flower", Google's own example.
- Broad, phrase and exact work differently as negatives than as bid keywords. The default, broad, is the most aggressive, not the safest.
- The search terms report has the real answers. A generic blocklist is a guess; your own data is evidence.
- You can hold up to 10,000 negative keywords per campaign, 1,000 at account level. Running out of room is rarely the problem.
- Over-blocking is a real, expensive failure mode. A few generic terms can cost more than the waste they stop.
What Negative Keywords Actually Are
A negative keyword is a type of keyword that stops your ad being triggered by a specific word or phrase. Google defines it plainly: it "prevents your ad from being triggered by a certain word or phrase." Add one and that search never shows your ad again, however relevant your other keywords look.
The useful model: your keywords describe who you want to reach; your negative keywords describe who you're willing to pay to reach. Most accounts are built carefully on the first half and left bare on the second, which is why budget drifts towards searches nobody chose to pay for.
A Peterborough web design agency bidding on "web design" ends up paying for "web design course", "web design salary" and "web design jobs" unless somebody tells Google Ads not to show for them. Three words of difference, and none of them is a customer.
One distinction worth being precise about: a negative keyword stops the ad showing. It doesn't lower your bid or let the ad run more cheaply. It's a hard exclusion: block too little and you keep paying for noise, block too much and you stop showing to people who would have bought.
The Part Google Documents and Almost Nobody Repeats
Positive keywords in Google Ads expand to match close variants: plurals, misspellings, synonyms, reordered words, related searches. Negative keywords do not. This asymmetry is arguably the single most expensive thing a UK advertiser doesn't know about the platform, and Google documents it plainly.
Google's own documentation states it directly: "Negative keywords won't match to close variants or other expansions." Its example: exclude "flowers" as a broad match negative, and your ad is blocked for "red flowers", but can still show for "red flower" (Google Ads Help, 2026).
There's one exception, and it matters because it stops you over-correcting. Google: "Negative keywords automatically account for casing and misspellings, so you don't need to add those separately." Casing and typos are handled for you.
Synonyms, singulars and plurals are not: "You'll need to add synonyms and singular or plural versions if you want to exclude them."
The practical consequence is blunt: every copied blocklist is leaking on exactly this. If "jobs" is on the list and "job" isn't, you're still paying for job hunters. If "course" is blocked and "courses" isn't, half the education traffic gets through. Check your own account: pairs like these are almost always there.
The Three Negative Match Types
Google Ads gives you three negative match types, and the default is the most aggressive, not the safest. Broad blocks a search containing all your terms in any order. Phrase blocks the exact phrase in that order. Exact blocks only that precise search with nothing added.
- Broad match negative (no punctuation, the default). Google: "your ad won't show if the search contains all your negative keyword terms, even if the terms are in a different order. Your ad may still show if the search contains only some of your keyword terms." Right for whole categories you never serve: free, jobs, course. The trap: it's easy to over-block, since order and extra words don't save you.
- Phrase match negative ("in quotation marks"). Google: "your ad won't show if the search contains the exact keyword terms in the same order." Right for a two or three word phrase you want gone in that order. The trap: reorder the words and the block does nothing.
- Exact match negative ([in square brackets]). Google: "your ad won't show if the search contains the exact keyword terms, in the same order, without extra words." Right when a term is a genuine customer search except in one form, for example [cheap web design] should go while "web design" stays. The trap: treating it as the safe default, when broad usually suits the category.
The three types aren't interchangeable: the wrong choice leaks traffic or blocks it by accident. Worth knowing what Google strips from a negative keyword: periods and usually plus signs are ignored, and site: is removed entirely. Ampersands, accent marks and asterisks are allowed as real characters (Google Ads Help, 2026).
Where the Real Answers Already Are: Your Search Terms Report
Your search terms report shows the actual searches that triggered your ads, not the keywords you chose to bid on in the first place. That distinction, chosen keyword versus actual search, is one many advertisers have never had properly explained to them.
Read it by sorting by cost, not impressions, and looking at spend with zero conversions over a window long enough to mean something, at least four to six weeks for most small accounts. Four patterns account for most of the waste in UK service accounts:
- Employment searches: jobs, salary, apprenticeship, vacancies
- Education searches: course, training, how to, tutorial, degree
- Free and DIY searches: free, template, download, plugin, yourself
- Wrong geography: towns and counties you do not serve, and national versions of local searches
A worked example from a Peterborough web design agency's account shows the pattern:
- "web design jobs peterborough": £38, 9 clicks, 0 conversions
- "web design course online": £22, 6 clicks, 0 conversions
- "free website builder": £19, 11 clicks, 0 conversions
- "web design london": £31, 7 clicks, 0 conversions (wrong area)
- "web design agency reviews": £14, 4 clicks, 1 conversion
- "ecommerce website design peterborough": £46, 12 clicks, 0 conversions (wrong landing page)
One honest limitation nobody else mentions: since 2020, the report hasn't shown every query. Low-volume searches are withheld for privacy, so some spend stays unattributable. Lean on broad category negatives and tighter match types; don't give up on the report because of it.
Block It, Keep It, or Split It Out
Every row in a search terms report needs one of three decisions: block it, keep it, or split it into its own ad group. Most advertisers only ever make the first two choices, and the third is usually where the money is.
- Block it. The search can never become a customer: the four zero-conversion rows above. Pick the match type from above (broad for a category, exact for a one-off), and send it to campaign level if it's wrong everywhere, or account level if it's wrong for every campaign.
- Keep it, despite looking wasteful. The trap case: "web design agency reviews" reads like research, but it converted, late-stage comparison shopping, not noise. The test is the data, not the wording. A term with spend and conversions stays, however irrelevant it looks; spend with no conversions but a plausible path to one needs more data, not a block.
- Split it out. The option almost nobody mentions: "ecommerce website design peterborough" is genuinely relevant but mismatched to the page it lands on. Blocking it loses a real customer; leaving it wastes the click. The fix is its own ad group, ad copy and landing page, so the ecommerce searcher gets ecommerce, not a generic pitch.
This sits inside the wider mechanics of paid search; our paid advertising guide covers the setup it slots into. Run the check weekly for the first month while an account calibrates, then monthly once it settles. An account with no negatives added in six months isn't running itself. It's drifting.
Need someone to run this every month? Brilliant Digital has managed Google Ads for UK small businesses since 2014, and a search terms review like this is part of the job. See how we manage Google Ads.
Why the List You Copied Is Costing You Customers
Search for a negative keyword list and you'll find thousands of terms, free, segmented, ready to paste in. Most are generic, copied wholesale, with no warning about who gets blocked. It feels like finishing the job in ten seconds. It usually isn't.
Terms straight off those lists cause real damage:
- "review" and "repair" block "best web design agency reviews" and "boiler repair": a supplier search, and the actual service, for any trade.
- "problem", "error" and "complaint" block people describing a symptom they're about to pay to fix.
- "job" blocks job hunters, but also "small job plumber" and "finish the job": customers.
- "cheap", "affordable" and "low cost" suit a premium position, wrong for anyone competing on value, a decision rarely made before the list gets pasted in.
The principle worth keeping: a negative keyword states that nobody using this word will ever buy from you. A generic list makes that statement on your behalf, having never seen your market. Three or four terms like that can cost more than the waste they prevented, and the loss is invisible: a blocked search never appears in any report.
A shorter, UK-specific list, rebuilt with a condition on every term, holds up better:
- Employment and education terms (jobs, vacancy, apprenticeship, salary, course, training, tutorial, free, template): block broad, only if you don't also hire, train or sell these yourself.
- Price-positioning terms (cheap, affordable, low cost, budget): block only if positioned at the premium end. Competing on price makes these customers, not noise.
- Out-of-area terms (towns, counties and regions you don't serve): block phrase match per place name, not a broad term that might catch areas you serve.
- Symptom and complaint words (review, repair, problem, complaint, error, job alone): leave alone by default. These overwhelmingly belong to real customers. Block only the exact phrase your report proves wrong, never the word alone.
Account, Campaign or Ad Group: The Real Limits
Negative keywords work at three levels, and the decision is mostly about scope. Account level is for junk wrong everywhere. Campaign level is for terms wrong here but fine elsewhere, where most negatives belong. Ad group level is a sculpting tool, stopping your own ad groups competing for the same search, not excluding bad traffic.
Account-level negative keywords apply broadly: Google states they automatically apply to "Search, Performance Max, App, Shopping, Smart and Local campaigns." Add a term once and it's excluded everywhere that matters, the level to treat with the most caution.
Negative keyword lists sit alongside this: build a shared list once, apply it to many campaigns, and update it in one place.
Verified against Google's current documentation, rarely stated anywhere else:
- 10,000 negative keywords per campaign
- 5,000 keywords per negative keyword list
- 20 negative keyword lists per manager account, plus 20 per child account
- 1,000 account-level negative keywords
- 1,000 negative keywords for Display Network and video campaigns
Running out of room is almost never the problem. Running out of judgement about what belongs on the list is.
What Changes in Performance Max and Shopping
Performance Max negative keywords behave differently to Search negatives, and it catches people out. Google is explicit: "Performance Max negative keywords are applicable to Search and Shopping inventory only." Negatives added to a Performance Max campaign do nothing for its Display or video inventory.
Advertisers add them, see no change in the placements bothering them, and conclude the feature is broken. It isn't; it was never meant to touch that inventory.
Add Performance Max negatives at campaign level through the Keywords section, under the Negative keywords tab. Account-level negatives flow in automatically, since they apply to all eligible Search and Shopping inventory across the account. Brand exclusions are a separate control, worth knowing if what you want is to stop showing against your own brand terms, not general irrelevant traffic.
Shopping campaigns are more straightforward: negatives work on search terms as expected, where blocking "used", "second hand" and competitor brand names earns its keep for a retailer.
One honest caveat: automated types like Performance Max give less visibility into what was blocked, which makes the verification loop above more important here, not less.
Frequently Asked Questions
What is a negative keyword example?
Excluding "free" as a broad match negative stops your ad showing for "free website templates" or "free web design course". Use exact match, [free website templates], if you only want to block that specific search while still showing for other searches that happen to contain the word "free".
How do I make a negative keyword list?
In Google Ads, go to Tools, then Shared library, then Exclusion lists, then Negative keyword lists. Create a list, add your terms with the match type, then apply it to as many campaigns as need it. Update the list once and every linked campaign updates.
Where do I find negative keywords in Google Ads?
Go to Campaigns, then Keywords, then the Negative keywords tab. Select the plus button to add a term directly to the campaign you have open, or to apply an existing negative keyword list instead of typing terms in one at a time.
Should negative keywords be exact match?
No, not by default. Broad match negative is usually right for whole UK categories you never serve. Exact match is right only when a specific phrase needs blocking while close variants of the same words should still be allowed through.
How many negative keywords can you have?
Up to 10,000 per campaign, 5,000 per negative keyword list, 20 lists per manager account plus 20 per child account, and 1,000 at account level. Display Network and video campaigns are capped at 1,000. Running out of room is rarely the real constraint.
Do negative keywords work in Performance Max?
Yes, but only for Search and Shopping inventory within that campaign. They do nothing for the Display or video inventory Performance Max also serves, which is the most common source of confusion about the feature for UK advertisers running these campaigns.
What to Do Next
If you're still weighing up paid search against organic altogether, our PPC vs SEO comparison is a good place to start. If you've already committed to Google Ads, here's something to do with this article in the next twenty minutes rather than just reading it.
Open your search terms report. Sort by cost. Find the five highest spenders with zero conversions, and run each through the block, keep or split decision above.
Brilliant Digital manages Google Ads for UK businesses, and this kind of review is part of what that involves, alongside the account structure and bidding strategy around it. If a campaign isn't delivering, or you're starting from scratch, get in touch about Google Ads management.
