Google Ads Negative Keywords: Stop Wasting Budget

The call usually comes a few months too late. The account has spent a real amount of money, the phone has not rung much, and the owner wants to know whether Google Ads works. By the time I open the search terms report, the answer is usually visible in a couple of minutes, and it is rarely about Google.

In 13 years of managing paid search for Australian businesses, the single most common fault I find is an account with no negative keywords in it at all. Not a short list that needs work. None. Every search query that Google could loosely connect to the keyword has been allowed to trigger the ad, and the budget has been quietly spent on people looking for something else.

This is written for the owner or in-house marketer who is looking at their own account and wondering why clicks are cheap and enquiries are not. The good news is that this is one of the few problems in paid search you can start fixing in ten minutes without spending anything.

What Wasted Spend Looks Like Before You Check

The enquiries that never arrive

There is no alarm for this. The account does not flag the money it spent on someone searching for a job, a free version, a second hand unit, or a competitor's name. What you notice instead is a pattern of behaviour in the business: plenty of clicks, sensible looking click costs, and a lead count that never quite matches what the spend should have bought.

Owners usually explain it with the market or the season. Sometimes that is true. More often, half the budget went to searches that could never have become a customer.

Ten minutes in the search terms report

The search terms report shows what people actually typed before your ad appeared. Not the keywords you bid on, the real queries. Open it, set the date range to the last 90 days, sort by cost, and read the top twenty terms. On most accounts that have never been cleaned, three or four of those terms will have nothing to do with the business. Those are the ones you block today.

Google's own guidance on the report is direct: "If a search term isn't relevant enough to the products or services you offer, add it as a negative keyword." You can read that on the help page about the search terms report. The same page explains why it matters: "By adding irrelevant search terms as negative keywords, you can prevent your ad from showing to people who are looking for something you don't sell."

What Negative Keywords Can and Cannot Do

Terms you exclude, not ideas you avoid

A negative keyword is a filter, not a judgement. It excludes searches containing the term you list, which means it works on the words someone typed rather than the intention behind them. That distinction explains most of the disappointment people have with them. Blocking the word free stops searches containing free. It does not stop someone who wants a cheap quote, and it will not stop a search that means the same thing in different words.

Used well, though, they do exactly what Google says: "Negative keywords let you exclude search terms from your campaigns and help you focus on only the keywords that matter to your customers." The same help page opens with a line I repeat to clients often, because it is the whole discipline in nine words: "One key to a highly targeted campaign is choosing what not to target." Both statements come from Google's page about negative keywords.

Where they stop working entirely

Negatives do not repair a keyword strategy that was wrong from the start. If the keyword list is built from what the business calls itself rather than what customers search for, blocking bad queries will trim the waste without producing enquiries. They also cannot make an ad relevant, and they cannot change what you pay for the clicks you keep. Treat them as a waste reduction job, and expect the account to feel tidier rather than transformed.

The Three Negative Match Types, Explained Plainly

Why broad is the default and what it blocks

Negative broad match is what you get when you add a term without any marks around it. The search has to contain all the words you listed, in any order, for the ad to be held back. Add second hand as a negative broad, and a search for second hand mowers and a search for mowers second hand are both blocked. A search for hand tools is not, because it does not contain both words.

This is the type to use when the theme is clear and the individual words are not risky. It is also the type that catches the most irrelevant traffic for the least effort, which is why most of a small account's negative list should be broad.

Phrase and exact, and the words in between

Negative phrase match holds your ad back when the search contains the phrase as written, even with other words around it. Negative exact match is tighter still: the search has to match your term with nothing added. The practical difference is precision. If you sell new office furniture and you never want to appear for used stock, a phrase negative on used office furniture blocks searches that include those words in that order, while an exact negative only blocks the search that matches it word for word.

Reach for phrase or exact when a broad negative would eat good traffic. A single broad word like commercial can be useful on one account and destructive on another, depending on how the business talks about itself.

Close Variants: The Trap Most Accounts Miss

Why your negative does not catch the plural

This is the part that catches people out, and it is worth reading twice. Google's help documentation states that "Negative keywords don't match to close variants, so your ad might still show on searches or pages that contain close variations of your negative keyword terms." Your positive keywords are matched loosely, including plurals, misspellings and reordered words. Your negative keywords are not. Block the singular and the plural can still reach you.

Adding what you actually need to add

The habit that fixes this is unglamorous. When you block a term, add the obvious variants in the same sitting: the plural, the common misspelling, and the other phrasing you saw in the search terms report. Two minutes of work, done once, prevents the search that brings the same wasted click back a month later under a slightly different spelling.

Account-Level Lists Versus Campaign Negatives

What belongs in each

An account-level negative keyword list applies to every campaign you attach it to. Campaign-level negatives apply only where you put them. The split that works is simple. Account-level lists carry the themes that are wrong for the whole business: job seekers, free seekers, DIY instructions, second hand, and the wrong product category entirely. Campaign-level negatives carry what only matters in one place, such as the service terms that conflict with a single campaign's offer.

Keep it that way and the account gets easier to manage as it grows. Mix them and you end up with a hundred campaign-level duplicates that nobody can safely edit.

Keeping the list from becoming a maze

Name your lists after the theme rather than the date, keep a short comment against anything unusual so future you knows why it is there, and resist adding a term to a campaign when it really belongs in the shared list. One large account I reviewed had eleven separate lists containing the same eight terms, which made it impossible to know which one was safe to change.

Over-Blocking: How Negatives Quietly Shrink Reach

The warning Google itself prints

There is a failure mode in the other direction, and Google documents it: "If you use too many negative keywords, your ads might reach fewer customers." An account that has been over-cleaned behaves like a campaign with a shrinking keyword list. Spend falls, cost per click looks fine, and the enquiries drop because there is simply less of the market left.

A review that protects reach

The check takes a minute. Look at your negative lists, and ask which of these terms was added because a search was genuinely irrelevant rather than because one expensive click annoyed someone. Terms added after a single bad day are the ones that quietly cost you business for a year. If you cannot remember why a term is on the list, suspect it before you defend it. The 1,000 keyword ceiling people worry about is not the real risk here, and it only applies to Display and Video ads, where Google's documentation notes that "For Display and Video ads, a maximum of 1,000 negative keywords is considered at the account level."

Finding the Terms Worth Blocking

The search terms report workflow

Work in this order and it takes a quarter of an hour. Sort the report by cost, read the top fifty terms, and highlight anything that could never become a customer. Then sort by impressions with a low click count, because a term with hundreds of impressions and one click is still costing you auction position. Then look at the terms with the worst conversion rate, which are usually the ones sitting closest to your actual offer and quietly soaking up budget.

Themes to block, not just single terms

One term handled well is worth more than twenty handled carelessly. If several unrelated searches share a theme, such as people looking for a job, people looking for a free template, or people looking for a product you stopped selling in 2022, add the theme as a small group of negatives rather than one word. That way the next variation is already covered, and you are not back in the same report next month with the same problem.

A Monthly Ten Minute Negative Keyword Routine

Open the search terms report for the previous month. Scan the top fifty terms by cost. Add anything irrelevant to the appropriate list, together with its obvious variants. Check the negative lists for anything that looks like it is blocking good traffic, and remove the ones you cannot justify. Check that your shared lists are still attached to the campaigns they belong to. Then close the report and do something more interesting.

That is the whole routine. What makes it work is the calendar entry, not the insight. Accounts go wrong slowly, one irrelevant click at a time, and ten minutes a month is what keeps the trend flat. If you would rather have a second set of eyes on it first, an independent Google Ads audit will read the search terms report line by line and name the themes that are costing you money.

It is also worth knowing what the account should be buying in the first place. If you are unsure whether the monthly number is sensible for your market, work out what your budget should be buying before you spend another month guessing.

What Good Looks Like After Ninety Days

Three months of the monthly routine changes the shape of an account. The share of spend going to genuinely relevant searches climbs, because the irrelevant themes have been removed rather than tolerated. The click count usually falls while enquiries hold or improve. Cost per click moves a little and matters less than the fact that a higher proportion of the spend is now aimed at people who could actually buy.

What you should not expect is a step change in the first fortnight. Negative keywords remove waste; they do not create demand. If the account still has no enquiries after a quarter of cleaning, the problem is upstream, in the keyword choice, the offer or the landing page, and that is a different piece of work. Ongoing management of the keyword structure is part of Google Ads management, and if the wider marketing mix is unclear, a wider marketing audit is the better starting point than another round of account tweaks.

Google Ads Negative Keywords FAQ

How many negative keywords do I need?

Fewer than most people add, and the right ones. A search account usually needs a short list of blocked themes rather than hundreds of individual words, added to an account-level list so it applies everywhere. Google's own guidance is that too many negatives can mean your ads reach fewer customers, so the aim is precision, not number.

Do negative keywords work on close variants?

No, and this is the most common misunderstanding in Google Ads. Google's help documentation states that negative keywords do not match to close variants, so blocking the singular or one spelling will not block the plural or an alternative phrasing. You have to add the variants you actually want excluded.

What is the difference between a negative keyword and a keyword I simply switched off?

A paused keyword only stops that keyword. A negative keyword stops any search term containing it, including searches matched by your other keywords and, on an account-level list, across campaigns. That is why negatives are the tool for themes, and pausing is the tool for single words.

Should I use an account-level negative keyword list?

Yes, once you have a stable set of themes you never want to pay for, such as job seekers, free seekers, or the wrong product category. Keep the campaign-level negatives for things that only matter in one campaign. Review both monthly, because an account that changes its offers will drift.

How often should I review search terms?

Monthly for most small accounts, weekly for anything spending meaningfully. The report shows what people actually typed, and Google's own recommendation is to turn an irrelevant search term into a negative keyword as soon as you see it. Left alone for a quarter, an account can accumulate hundreds of irrelevant clicks.

Can negative keywords fix high cost per click?

They reduce the money spent on queries you do not want, which improves the account's overall efficiency, but they do not change what you pay for the clicks you do want. Treat them as a waste reduction exercise and judge them on wasted spend removed, not on cost per click alone.