Negative keywords are the most underappreciated efficiency lever in Google Ads. Most advertisers focus on which keywords to bid on; fewer pay equal attention to which searches they should actively exclude. A well-maintained negative keyword list can reduce wasted ad spend by 20 to 40% in most accounts, routing budget from irrelevant searches to the queries that actually convert. For UK businesses paying between £2 and £50 per click, this efficiency improvement is directly measurable in monthly savings.
What Are Negative Keywords and Why Do They Matter?
A negative keyword is a word or phrase that, when present in a search query, prevents your ad from showing. If you sell premium office furniture and add "cheap" as a negative keyword, your ad will not show for "cheap office chairs," "cheap office desks," or any other query containing the word "cheap." This filters out price-sensitive searchers who are unlikely to become customers at your price point.
Negative keywords matter because broad and phrase match keywords in Google Ads can trigger ads on a wide range of loosely related searches. A campaign targeting "accountant London" on broad match might show for "accounting software London," "student accountant jobs London," or "accountant CV template London." None of these searches indicate purchase intent for an accounting firm's services, yet each click at £5 or £10 per click depletes your budget.
Google's Smart Bidding algorithms have improved significantly in recent years, but they still require a solid foundation of negative keywords to prevent systematic waste. Smart Bidding cannot override your keyword match type settings to avoid irrelevant queries; that is a human decision.
How Do You Find Negative Keywords for Your Account?
Search Terms Report
The search terms report is the most important source of negative keyword opportunities. It shows you the exact queries that triggered your ads and led to clicks, regardless of which keyword those queries matched. Navigate to Keywords > Search Terms in the Google Ads interface and filter by date range (at least 30 days).
Sort by spend or click volume and review every query. For each one, ask: "Is this search from someone who might buy from me?" If the answer is no, add it as a negative keyword.
Patterns to watch for:
- Informational queries: "How to do X," "what is X," "X tutorial," "X guide": users seeking free information, not purchasing services
- Irrelevant geographic modifiers: If you only serve UK clients but your ads are showing for US searches, add US location names as negatives
- Competitor queries: If competitors are showing for your keywords (which is normal), you may be showing for competitor-specific queries like "[Competitor] pricing"; add competitor brand names as negatives unless you are running a competitor campaign
- Job and careers queries: "[Your industry] jobs," "careers in X," "X salary": people looking for employment, not services
- Student or education queries: "X essay," "X assignment help," "X course": students researching topics, not buying
- DIY and free-tool queries: "Free X," "DIY X," "X template free," "X checklist download"
Think About Your Customers' Research Journey
Your target customers research before buying. What do they search for when they are not yet ready to buy? Add those queries as negatives to prevent paying for early-stage research clicks.
A law firm targeting "employment law advice" might find its ads showing for "employment law essay questions," "employment law student forum," and "employment law case studies UK." These are legitimate employment law searches, but not from people seeking legal representation.
Industry-Specific Negative Keywords
Every industry has characteristic irrelevant query patterns:
- B2B services: Add consumer-oriented terms, student and education terms, job-seeking terms
- High-ticket products: Add "cheap," "budget," "discount," "free," "DIY," "how to make your own"
- Local services: Add location names you do not serve; add "remote" or "online" if you only operate in person
- Professional services: Add "jobs," "salary," "internship," "training course," "certification," "how to become a"
How Should You Organise Your Negative Keywords?
Shared Negative Keyword Lists
Google Ads allows you to create shared negative keyword lists that can be applied across multiple campaigns simultaneously. This is far more efficient than adding negatives campaign by campaign.
Build shared lists for:
- Universal negatives: Terms that are irrelevant to your entire business (competitor brand names, "jobs," "free," "DIY," "training"). Apply this list to all campaigns.
- Category-specific negatives: Terms that are irrelevant to a specific category of campaigns but not all campaigns. An agency might have a universal "jobs" negative list, plus a separate "seo specific negatives" list only applied to SEO campaigns.
Match Type for Negative Keywords
Negative keywords use three match types:
- Broad match negative: Prevents your ad from showing when all words in the negative keyword appear in the query in any order. Use for concepts you want to exclude completely.
- Phrase match negative: Prevents showing when the exact phrase appears in the query. Use for specific phrases where the word order matters.
- Exact match negative: Only prevents showing when the query exactly matches the negative keyword with no other words. Use sparingly; it is the least efficient for filtering broad irrelevance.
For most negative keywords, phrase match is the most efficient choice. It catches queries containing the phrase while allowing your ads to show for unrelated queries that happen to contain the same word in a different context.
What Are the Most Common Negative Keyword Mistakes?
Not Running the Search Terms Report Regularly
The search terms report must be reviewed every two to four weeks in active campaigns. As Google's match types broaden and as search behaviour evolves, new irrelevant queries will emerge. Skipping this review for three months can mean thousands of pounds in wasted spend on irrelevant traffic.
Adding Too-Broad Negatives That Block Legitimate Traffic
Excessive negative keyword use blocks relevant traffic. If you add "free" as a broad match negative, you will prevent your ads from showing for queries like "first month free," "free trial," "free estimate," and similar phrases that may contain your target audience. Be specific: "free SEO guide" rather than "free."
Using Only Exact Match Negatives
Many advertisers add negative keywords in exact match, which means only that precise query is blocked. Broad and phrase match negatives are significantly more efficient at filtering irrelevant traffic at scale.
Not Applying Negatives at the Right Level
Negative keywords can be applied at the account level (via shared lists), campaign level, or ad group level. Apply universal negatives at the account level for efficiency. Apply category-specific negatives at the campaign level. Reserve ad group level negatives for cases where a specific ad group needs fine-grained exclusion (for example, when two ad groups in the same campaign are targeting competing match types for related queries).
How Do You Maintain a Negative Keyword List Over Time?
Build a regular cadence:
- Weekly: Scan the search terms report for new irrelevant queries in high-spend campaigns. Add obvious negatives immediately.
- Monthly: Full search terms review across all campaigns. Assess whether existing negatives are still necessary (some may have been added for temporary campaigns).
- Quarterly: Review your shared lists and remove any negatives that have become too restrictive as your products or services have evolved.
Document the rationale for any non-obvious negative keywords you add. Three months later, when a campaign manager (or you, having forgotten the reasoning) questions why a specific term is excluded, having a note explaining the decision saves time and prevents accidental removal of important negatives.
Dynamically runs monthly search terms reviews as a standard component of every PPC account we manage. If your account has accumulated months of unchecked search term waste, get in touch for a PPC audit that quantifies exactly how much could be saved.
