What are Google Ads negative keywords and why do e-commerce stores need them?
Negative keywords are terms that stop your ads from showing on irrelevant searches. For an e-commerce store, they block informational queries, competitor brand names, and off-niche traffic so your budget concentrates on commercial intent. A well-maintained negative keyword list typically recovers 15-25% of wasted spend without touching bid strategy or budgets, because the money that stops flowing to irrelevant searches concentrates on the queries that actually convert.
Most e-commerce accounts running without active management have zero negative keywords applied. The Search Terms report tells the story: spend flowing to "how to clean [product]", "[brand] Wikipedia", "DIY [product]", "cheap [product] from China", and competitor brand names. None of those searchers are buyers. The fix costs nothing extra to run, it just requires knowing where to look and what to exclude.
Why E-Commerce Accounts Lose Budget to Searches That Will Never Convert
In every account we audit at Social Surge, the same pattern appears: campaigns running for months with no negative keywords in place. Broad match and Performance Max are aggressive by design. Google's systems optimise for clicks and conversions, and in the early weeks of a campaign they test a wide range of queries, some useful, most not. Without negatives in place, you fund that experiment indefinitely.
The problem is not that Google's matching is broken. It is that the default is to expand reach and let performance data prune what does not work over time. For a small e-commerce account, that timeline is expensive. A query spending £3 per click with no conversion history stays in rotation until someone removes it. Multiply that across dozens of irrelevant terms and the monthly waste quickly reaches hundreds of pounds.
In the accounts we take over, a Search Terms audit is the first task after onboarding. The irrelevant spend we find consistently surprises owners who have been managing campaigns themselves. A free PPC audit will surface exactly this pattern in your own account, with a line-by-line breakdown of where budget is going.
How to Find Wasted Spend Using the Search Terms Report
In Google Ads, navigate to Campaigns, then Insights and reports, then Search terms. Set a date range of at least 90 days and sort by Cost descending. Look for:
- Informational intent: queries starting with "how to", "what is", "review", "vs", or "best" that have spend but zero conversions
- Wrong geography or currency signals: searches implying delivery expectations you cannot meet, or prices in currencies you do not support
- Competitor brand names: these typically convert at high CPA unless you have a deliberate conquest strategy in place
- Off-niche modifiers: size, colour, or material variants you do not stock, or price signals that attract bargain hunters well below your margin floor ("free", "second hand", "cheap")
- Irrelevant product categories: adjacent searches that match a broad keyword but describe a completely different product
Export the report. Filter for zero conversions and cost above your target CPA. Every row on that filtered list is a candidate for a negative keyword. This exercise typically surfaces £200-£2,000 of monthly wasted spend in accounts running at £3,000-£10,000 per month, and it takes less than an hour once you know what to look for.
Building Your E-Commerce Negative Keyword Starter List
A solid starting list for most e-commerce Google Ads accounts covers four main categories. Add these as phrase match negatives at campaign level across all relevant campaigns.
Informational modifiers: "how to", "what is", "diy", "tutorial", "guide", "review", "reviews", "vs", "versus", "wiki", "wikipedia", "history of", "manual", "repair", "fix", "tips"
Availability and condition signals: "second hand", "used", "refurbished", "donated", "free", "borrow", "rent"
Job and career terms: "job", "jobs", "vacancy", "vacancies", "career", "careers", "salary", "apprenticeship", "hiring", "graduate"
Price-sensitivity signals (for premium positioning): "cheap", "budget", "bargain", "discount code", "voucher code" (remove these if price is your actual selling point)
For category-specific exclusions, such as a cycling store needing to block fishing queries that might match a broad "rod" keyword, add those at campaign level too. Google Ads Help has a clear walkthrough on how to add negative keywords and the match type options available for each campaign type.
Negative Keywords in Performance Max: What Is Different
Performance Max does not expose a full Search Terms report the way standard campaigns do. As of late 2026, Google provides search term themes within PMAX insights, but individual query visibility remains limited compared to Search or Shopping campaigns. This makes identifying the specific waste harder, not impossible.
For PMAX negative keywords, the most reliable options are:
- Account-level negative keyword lists: Create a shared list in Tools and Settings, then Shared Library, then Negative keyword lists, and apply it to your PMAX campaign. This is the most dependable method and ensures the same exclusions apply consistently across all campaign types.
- Campaign-level negatives: You can add negatives directly inside a PMAX campaign via its settings. The interface is less prominent than in standard campaigns, but the exclusions work reliably.
- Brand exclusions: PMAX has a dedicated brand exclusions setting that prevents your ads from serving on brand-name searches. This is essential if you run a separate brand campaign alongside PMAX, to keep traffic cleanly separated and protect brand ROAS figures.
In the accounts we manage, we apply a core account-level negative list at launch and expand it as the campaign matures and search term theme data accumulates. For a broader look at PMAX trade-offs, our guide on Performance Max vs Standard Shopping covers when each campaign type makes sense for UK e-commerce stores.
Campaign-Level vs Ad Group-Level: Where Do Negatives Belong?
Getting this structure right avoids both gaps in coverage and unnecessary maintenance overhead.
- Campaign-level: Use for exclusions that apply to all ad groups within a campaign. Irrelevant product categories, informational modifiers, geographic signals. This is where roughly 80% of negatives should live.
- Ad group-level: Use for cross-pollution prevention within a single campaign. In a campaign covering both road bikes and mountain bikes, for example, exclude "mountain" at ad group level within the road bike ad group to prevent irrelevant matching across your own inventory.
- Account-level shared lists: Use for universal exclusions that apply site-wide: job-related terms, unambiguous competitor brand names (if you never run conquest), and your own brand in non-brand campaigns.
Over-applying ad group-level negatives creates maintenance overhead without adding meaningful precision. Default to campaign-level and move down only when you have a specific, documented reason to do so.
Common Mistakes That Quietly Increase Wasted Spend
Exact match only: If you add [cycling gloves waterproof] as an exact match negative, you miss "waterproof cycling gloves" and dozens of other arrangements. Phrase match negatives block the term wherever it appears in a search and are the right default for most exclusion lists.
Blocking converting queries by accident: Before adding a negative, check whether that term already converts. Sort the Search Terms report by conversions before acting on zero-conversion rows. Removing a query that drives sales is an easily avoided mistake that can quietly tank revenue.
Neglecting the list after launch: A negative keyword list built in month one will not cover the new irrelevant queries that emerge as match types evolve and Google tests new territory. Review the Search Terms report weekly for active campaigns, or at minimum once a month, and treat it as a recurring task rather than a one-time setup.
Skipping account-level lists for PMAX: Adding negatives directly inside a PMAX campaign without also applying an account-level list can lead to inconsistent coverage as campaigns update. The shared list approach is more reliable and easier to audit.
If campaigns are still not converting after a thorough negative keyword review, our post on why Google Ads are not converting for e-commerce covers the other root causes in detail, including bidding, landing pages, and conversion tracking. Our Google Ads management service includes ongoing Search Terms review as a standard part of every account we run, with changes logged weekly so you can see exactly what was excluded and why.
Frequently Asked Questions
What are Google Ads negative keywords and why do e-commerce stores need them?
Negative keywords are terms that stop your ads from showing on irrelevant searches. For an e-commerce store, they block informational queries, competitor brand names, and off-niche traffic so your budget concentrates on commercial intent. Reviewing them regularly is one of the fastest ways to improve ROAS without increasing spend.
How many negative keywords should an e-commerce Google Ads account have?
There is no fixed target. A new account typically starts with 50-100 carefully chosen phrase match negatives, and that list grows as you review the Search Terms report each week. Accounts we work on typically reach 200-400 negatives within the first 90 days of active management.
Do negative keywords affect Quality Score?
Not directly. Quality Score is calculated at keyword level and reflects expected click-through rate, ad relevance, and landing page experience. Negative keywords improve the signal-to-noise ratio in your account, which can indirectly support better Quality Scores over time by directing spend toward queries where your ads perform well.
How do I add negative keywords to a Performance Max campaign?
The most reliable method is to create a shared negative keyword list at account level in Google Ads (Tools and Settings, then Shared Library, then Negative keyword lists) and apply it to your PMAX campaign. You can also add negatives directly at campaign level within PMAX settings. For brand exclusions specifically, PMAX has a dedicated brand exclusions option in campaign settings.
What match type should I use for negative keywords in Google Ads?
Phrase match is the right default for most negative keywords. It blocks the specified term and its close variants whenever the phrase appears in a search, without requiring you to list every possible word order. Use exact match negatives only when you want to exclude a precise search term without blocking broader contexts that contain similar words.
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