Google Ads Negative Keywords: A Plain-English Guide With Starter Lists for Home Services

Google Ads negative keywords are words and phrases you tell Google never to show your ads for. If you are an electrician paying for “emergency electrician”, a negative keyword such as “apprenticeship” stops your ad appearing, and costing you money, when someone is really looking for a training course.

A common problem in small accounts is that nobody has told Google what to ignore, so the ads quietly show for job seekers, students, DIYers and people hunting for a free answer. This guide explains what negative keywords are, how the three match types behave, where to add them, and gives you starter lists for plumbers, heating engineers, electricians and roofers that you can adapt in an afternoon.

What are negative keywords in Google Ads?

Negative keywords are search terms you exclude so your ads do not appear when someone types them. Google Ads decides which searches can trigger your ad, based on your keywords. A negative keyword overrides that decision for any search containing the word or phrase you excluded.

For a business owner, the point is simple. Every click costs money, and a click from someone who wanted a plumbing course is worth nothing to a plumber. Negative keywords are the main control you have over which searches you pay for, and they cost nothing to add.

They are also different from fixing click fraud. A negative keyword blocks a type of search. It cannot tell whether the person behind a perfectly sensible search is real. We come back to that near the end.

Why negative keywords matter more than they used to

Negative keywords matter because Google matches your ads to a wider set of searches than the keywords you typed in. Over the years Google has loosened how closely a search needs to resemble your keyword before your ad can show. Broad match, automated bidding and newer features all lean on this flexibility, and our guide to Google AI Max explains how far some of those settings can stretch.

That flexibility can find you customers you did not think of. It also finds people you would never choose. Your keyword list says what you want. The search terms report says what you actually paid for. Negative keywords are how you close the gap between the two.

If you want the wider picture of where budget leaks, our guide to Google Ads wasted spend covers six leaks, and negative keywords fix the first, and usually the biggest, of them.

Find what to exclude: the search terms report

The best list of negative keywords is the one your own account hands you. The search terms report shows the real phrases people typed before clicking your ad, along with what each click cost. Google describes it in its own search terms report help page.

Open it, set the date range to the last 90 days, and sort by cost with the highest first. Read down the list the way you would read a customer’s voicemail. For every phrase, ask one question: would I be happy to take this call?

Sort what you find into three piles.

The first pile is clearly wrong: job searches, courses, free advice, products you do not sell. These go straight onto your negative list.

The second pile is clearly right: “boiler repair near me”, “emergency plumber”, “roof leak repair”. Leave these alone, and consider adding them as proper keywords.

The third pile is uncertain: “boiler price”, “how much to rewire a house”. Do not exclude these yet. People researching cost are often close to buying, and we look at that judgement call below.

If your account has had a lot of traffic, the report will be long. Start with the 20 most expensive irrelevant phrases. Those usually account for most of the waste, and you can return for the rest later.

Negative keyword match types explained

Negative keywords have three match types, and they work differently from the match types on your normal keywords. Getting this wrong is the most common mistake, because a negative can either do nothing or block far more than you meant. Google sets out the rules in its negative keywords help page, and this is the short version.

Broad match negative is the default. Your ad is blocked only when the search contains all of your negative words, in any order. If you add boiler course as a broad match negative (typed without quotation marks or brackets), the search “course for boiler engineers” is blocked, but “boiler servicing” still shows your ad because it does not contain “course”.

Phrase match negative blocks searches that contain your words in the same order, with other words allowed around them. You write it with quotation marks, like “boiler course”. It would block “online boiler course” but not “course for boiler engineers”.

Exact match negative blocks only that exact search with no extra words. You write it in square brackets, like [boiler course]. It is the most precise option and the safest when a word is also part of a search you want.

One rule catches many people out. Negative keywords do not expand to close variants the way ordinary keywords do. If you exclude “course”, Google will not automatically exclude “courses”. You need to add the singular, the plural and the common alternatives yourself. Capital letters and misspellings are handled for you, but different word forms are not.

A good habit is to use phrase match for most of your negatives, broad match for single words that are never useful to you, and exact match when you need to protect a similar search you want to keep. Your broad single-word negatives also need a gut check, because a single-word broad negative blocks every search containing that word.

How to add negative keywords in Google Ads

You can add negative keywords at three levels, and the right level depends on how wide you want the block to be. The wording of menus in Google Ads changes from time to time, so look for the same ideas even if a button has moved.

The quickest route is straight from the search terms report. Tick the search terms you do not want, choose the option to add them as negative keywords, pick a match type, and choose where to apply them. This is how most owners work, and it takes about a minute per batch.

You can also add them at campaign level, which applies the block to one campaign only. This is useful when one campaign sells something another does not. A drain unblocking campaign and a boiler installation campaign should not necessarily share the same exclusions.

The third option is a shared negative keyword list, which you build once and attach to several campaigns. Google also supports an account-level list that applies across eligible Search and Shopping campaigns, according to the same help page. For a business with two or three campaigns, a shared list for the universal exclusions (jobs, courses, DIY) saves you from adding the same words again and again.

Whichever route you use, give each list a plain name such as “Universal exclusions” or “Boiler campaign exclusions”. Future you, or a small agency picking up the account, will thank you.

Not every campaign type treats negatives in the same way, and Google’s rules for newer automated campaigns have changed over time. Check Google’s help pages for the campaign type you use before assuming a list will apply.

Starter negative keywords for home services

A starter list saves you from waiting for wasted clicks to appear in your report. The terms below are examples to adapt, not a list to paste in blindly. Each trade has its own risks, and a word that is useless to a roofer might be gold to a locksmith.

Everyone in home services can usually exclude the same families of searches. Job and career searches are the biggest: jobs, job, careers, vacancies, hiring, salary, apprenticeship, apprentice, recruitment. Training searches come next: course, courses, training, qualification, certificate, NVQ, college. Then there is learning-for-free intent: diy, tutorial, youtube, how to, guide, video, forum, reddit, pdf, template. Finally, shopping for parts rather than hiring a person: wholesale, supplier, suppliers, trade counter, second hand, used, spare, spares.

For plumbers and heating engineers, add searches that point to product research or other services you do not offer. Examples include the names of high street plumbing retailers if you do not sell products, “boiler manual”, “boiler error code” or “boiler fault codes” (people trying to fix their own boiler), “radiator paint”, “pipe fittings” and “plumbing supplies”. Be careful with “repair” and “fix”. People who search “fix leaking tap” may be DIYers, but they are also exactly the customers who are about to give up and call someone.

For electricians, consider “electrician salary”, “electrician training”, “part p course”, “wiring diagram”, “plug wiring”, “fuse box diagram”, and “how to change a light bulb”. If you only do domestic work, you might add “industrial” and “commercial”, but only if you are certain. If you only do commercial work, reverse it.

For roofers, think about “roofing felt”, “roof tiles price list”, “roofing supplies”, “roofing jobs”, “roof tiles for sale”, “shed roof”, “flat roof diy” and “roofing felt how to”. Check “shed roof” against your own work first, as some roofers do take those jobs.

For all trades, the search terms report beats any list we can give you. A list is a starting point, and your account will tell you the rest within a few weeks.

The mistakes that cost you real enquiries

Negative keywords can cost you leads as easily as they save money, because over-blocking is invisible. You never see the searches your ad did not show for. A few habits prevent most damage.

Do not add single-word negatives from guesswork. Excluding “cheap” feels sensible until you realise some customers use it to mean affordable. Excluding “free” looks just as safe, but it also blocks “free quote”, which is exactly the search you want to keep. If in doubt, use phrase or exact match so you block only the search you have actually seen.

Do not negate the thing you sell. A heating engineer who adds “boiler” as a broad negative to stop “boiler course” has just switched off most of the business. This happens, and it is why a quick test is worth doing. Read your list aloud and ask whether any single word on it appears in your best-converting search.

Do not confuse research with time wasting. Searches like “how much does a new roof cost” or “boiler replacement cost” look like window shopping but are often the first step of a real purchase. If you can answer them well on your website, they can be worth keeping. If those searches bring clicks but no enquiries, our guide to Google Ads not converting covers the other causes to check before you blame the keyword.

Do not set it and forget it. The searches people use change with the seasons. A plumber sees frozen pipe searches in January and “tap dripping” all year round. Check the report monthly, and more often in the first month after you launch a campaign or change your keywords.

Negative keywords cannot fix location problems or bad traffic

Negative keywords control which words trigger your ad, but not where the searcher is or who they are. It helps to be clear about what they do not do, so you do not blame them for problems they cannot solve.

If you are getting clicks from the wrong town, that is a settings problem. Our guide to Google Ads location targeting explains how people outside your service area still see your ads, and how to fix it. If your ads are showing on partner websites you never chose, our explanation of Google Search Partners covers the opt-out.

The same limit applies to automated or fraudulent clicks. A bot can type “emergency plumber” as easily as a customer can. Your search terms report will show a sensible phrase and a perfectly respectable click, and no negative keyword can tell the difference. This is why a clean negative list and a click fraud tool solve different problems.

For context, campaigns running without anti-fraud tools had a fraud rate of 10.9 per cent in 2024, according to the IAS figure on the ClickGuardian click fraud statistics page. That page also warns against trusting industry-specific percentages, so treat that number as a general reference point rather than a prediction for your trade. The better test is your own account: if the search terms look clean but a chunk of the spend still produces nothing, the cause may be traffic quality rather than keywords.

Keeping your negative list tidy as your account grows

A small amount of structure stops a negative list becoming a mess. Keep one shared list for exclusions that apply to every campaign, and separate lists for exclusions that apply to one service. Group the words by theme, so jobs and training terms sit together and you can see at a glance what is covered.

Keep a note somewhere, even a simple spreadsheet, of why you added anything unusual. Six months later you will not remember why “shed” is on the list, and neither will the agency that takes over. If you ever need an audit, our ten-step Google Ads audit includes a negative keywords check alongside the other basics.

Negative keywords deal with irrelevant clicks. If you want a rough idea of what invalid clicks cost your business each month, the ClickGuardian ROI calculator lets you put in your own spend and see the effect, and it only takes a minute.

For trades and other local services, our industry guides show the particular traffic problems each sector runs into, and the glossary explains any PPC term in this article that you want to look up.

Frequently Asked Questions

What are negative keywords in Google Ads?

Negative keywords are words or phrases you tell Google Ads not to show your ads for. If a search contains your negative keyword, your ad is blocked for that search, so you stop paying for clicks from people who are clearly not looking for your service. For a plumber, typical negatives are “jobs”, “course” and “diy”.

How do I add negative keywords in Google Ads?

The easiest way is from the search terms report. Select the irrelevant searches, choose to add them as negative keywords, pick a match type, and apply them to an ad group, a campaign or a shared list. You can also add them directly in the keywords section of a campaign. Menu names change occasionally, so look for the negative keywords option.

What is the difference between broad, phrase and exact match negative keywords?

A broad negative blocks searches containing all your words in any order. A phrase negative blocks searches containing your words in the same order, with extra words allowed. An exact negative blocks only that exact search. Unlike ordinary keywords, negatives do not include close variants, so you must add plurals and alternative spellings yourself.

How many negative keywords should I have?

There is no ideal number. A small business account often needs a few dozen at the start and adds more each month as the search terms report shows new irrelevant searches. Quality matters more than quantity, because too many broad negatives can block genuine customers. Check your list regularly and remove anything that blocks searches that convert.

Can negative keywords stop click fraud?

No. Negative keywords block types of search, not types of visitor. A bot or a competitor can click your ad after a perfectly relevant search, which no negative keyword will catch. Negative keywords reduce irrelevant clicks, while click fraud protection looks at who is clicking and how they behave, so most advertisers benefit from both.

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Last updated: October 2026. Related ClickGuardian resources: the click fraud statistics page, our industry guides for home services, the glossary of PPC terms, and the ClickGuardian ROI calculator to estimate what invalid clicks are costing your own campaigns.