You open a Performance Max report expecting to review a healthy stream of sales or leads. Instead, the Search terms view is full of job searches, repair queries, free alternatives and competitor names. The campaign hasn't necessarily failed, but Google is spending against intent your business never agreed to serve.
That's where Performance Max negative keywords become a governance tool, not just a cleanup tactic. The difficult decision isn't finding a way to add exclusions. It's deciding which exclusions should affect one campaign and which should apply across the account, while avoiding the close-variants trap that can remove profitable demand without making the mistake obvious.
Why Your PMax Spend Is Slipping and What Negatives Can Fix
A typical clean-up starts with an uncomfortable conversation. A retailer sees that PMax has generated conversions, but the Search terms report also contains queries from people looking for jobs, free versions, repairs or products the retailer doesn't sell. The campaign's automation has found attention, but not all of that attention represents a viable buyer.
Performance Max can use broad signals across Google's inventory, including Search, Shopping, Display, YouTube and Discover. It doesn't operate like a conventional Search campaign built around a tightly controlled keyword set. Audience signals, creative assets, product data and landing pages help guide delivery, but they don't give you a direct exclusion for every unwanted query theme.
A negative keyword is the clearest query-level lever available inside PMax. It tells Google that a term or match pattern shouldn't qualify for relevant Search and Shopping inventory. That makes it useful for removing obvious intent mismatches while leaving bidding, asset rotation and broader automation in place. Guidance on controlling Google's automated campaigns in Performance Max is useful context, but the practical issue remains the same: automation needs boundaries.
Practical rule: A negative keyword should describe an intent you can defend excluding, not a query that merely looked unhelpful once.
There are important limits. Google support documents state that campaign-level negative keywords can support up to 10,000 keywords per Performance Max campaign, while account-level exclusions are capped at 1,000 terms. Those limits are documented in Google Ads support guidance, and they make scope a planning decision rather than a minor settings choice.
Negative keywords also don't create traditional Search-style control over every placement. They are designed for Search and Shopping inventory in PMax, so they won't replace placement, content or brand controls elsewhere. The right approach is therefore governance: define what belongs globally, what belongs locally, how exclusions are tested, and how every change is reviewed later.
Campaign Level Versus Account Level Explained
A PMax campaign for replacement parts may need to exclude “jobs”, while a campaign for servicing plans could need that same query. Campaign-level negative keywords stay inside one PMax campaign. Account-level negative keywords apply across eligible campaigns, so a decision made for one product range can restrict unrelated Search, Shopping or PMax activity.
Google's documentation gives campaign-level PMax negatives a limit of 10,000 keywords per campaign, compared with 1,000 keywords at account level. The higher campaign allowance supports detailed, local governance. It is not a reason to upload every poor query without reviewing intent, products and landing pages.
Campaign-level negatives are configured within the campaign's keyword controls. Account-level exclusions are managed at account scope and can affect matching beyond the PMax campaign where the exclusion was first considered. That wider reach can protect future launches when a term is universally irrelevant, but it also makes mistakes harder to spot and reverse.
| Feature | Campaign-Level | Account-Level |
|---|---|---|
| Scope | Applies to the selected Performance Max campaign | Applies across eligible campaigns in the account |
| PMax allowance | Up to 10,000 keywords per campaign, as documented by Google Ads | Up to 1,000 keywords, as documented by Google Ads support guidance |
| Best use | Product, asset-group or campaign-specific intent exclusions | Terms that should never trigger relevant activity anywhere |
| Main risk | Repeated maintenance across campaigns | Suppressing valid demand in unrelated campaigns |
| Review requirement | Check the campaign's products, offers and landing pages | Check every affected campaign before applying |
Why shared lists cause confusion
Search advertisers often expect a negative keyword list to behave identically across campaign types. PMax requires a scope check. Google supports direct campaign-level entry, reusable lists and match-type symbols, but the list still needs to be attached to the intended campaigns. An account-level exclusion can reach a new Search campaign that was built months later for a different offer.
Consider “repair”. It may be irrelevant for a retailer selling only new products, yet commercially relevant to a business selling servicing plans. Applying it globally would remove demand that another campaign is designed to capture.
Use clear naming and change records as part of your campaign organisation practices. Record the scope, excluded intent and affected campaigns, then review the decision before applying it account-wide. Keep campaign-level negatives for exceptions tied to a product, offer or landing page. Reserve account-level negatives for language the business would reject regardless of campaign.
Mining Search Terms and Applying Negatives
Start with evidence, not a brainstormed list. Open the PMax campaign and review its Insights and Search terms information, then use the account-level Search terms report to examine the queries that have surfaced from PMax activity. PMax isn't keyword-targeted in the traditional sense, but the report still gives you visibility into the search intent Google matched.
The first pass should identify themes rather than isolated wording. Look for job-seeker language, support requests, DIY research, free alternatives, competitor brands and queries that describe a product or service you no longer offer. A query with no conversion isn't automatically a negative, so check its cost, relevance, landing page and place in the buying journey before excluding it. Resources on keyword research for PPC can help separate genuine commercial intent from wording that only looks similar.
Applying a small set quickly
For a handful of clear exclusions, use the negative action available from the Search terms report. The red Negatives column can turn an observed query into a campaign-level exclusion without forcing you to build a separate spreadsheet first. Confirm the selected scope before saving, especially if the account contains several PMax campaigns with different products.
For a larger clean-up, move to the campaign's Keywords > Negative keywords area. Enter terms one per line, use the supported match-type symbols deliberately and keep the upload sheet clean. Separate universal themes from campaign-specific phrases before importing, rather than deciding scope while clicking through the interface.
A negative applied to PMax affects matching within its supported Search and Shopping inventory. It isn't a Search-only switch, so check the campaign's product range and landing pages before excluding a broad term. Google also notes that brand exclusions may be more suitable for blocking your own brand variants, including misspellings and foreign-script variants that negative keywords may not catch.
Once the first batch is saved, return to the Search terms report and compare the new query mix with the previous review. Don't judge the change solely by whether irrelevant queries disappear. Check whether relevant query coverage, conversions and spend remain consistent with the campaign's commercial purpose.
The workflow should feel deliberately boring. Find a pattern, classify its scope, apply a small batch, document the reason and review what changed.
Choosing the Right Scope for Each Exclusion
Scope is a governance decision. The correct question isn't “Can I block this term?” It's “Would I defend blocking this theme from every campaign this account may run?”
Use account-level exclusions only for terms that are irrelevant across the entire business. Examples can include job-seeker intent, clearly unwanted freebie language, DIY research, used or broken-product intent, and competitor names that the business has explicitly decided not to target. Even then, check whether a Search campaign or service line has a legitimate reason to use that language.
Keep campaign-level negatives for exclusions connected to a particular product group, asset group, offer, season or commercial constraint. A product line may no longer be available in one PMax campaign while another campaign still sells a related version. A price-related term might be unsuitable for a premium campaign but valuable for a budget range.
| Question to ask | Use account-level, 1,000-term cap | Use campaign-level, 10,000-term cap | Example query theme |
|---|---|---|---|
| Is it irrelevant everywhere? | Yes, after checking all campaigns | No | Jobs or clearly unrelated employment intent |
| Does the exclusion relate to one product range? | No | Yes | A discontinued product variant |
| Could another campaign convert on it? | Avoid account scope | Keep it local | Repair or refurbished intent |
| Has the theme wasted budget across several campaigns? | Consider a governed account rule | Use local exclusions while validating | Repeated competitor queries |
| Would reversing the decision be difficult? | Apply only with strong evidence | Prefer local scope first | Broad price or condition language |
Three questions settle most disputes:
- Business-wide relevance: Is this query theme wrong for every offer, or only for the campaign currently showing it?
- Cross-campaign risk: Could another campaign legitimately convert on the term?
- Future volume: Is the theme common enough that relying on memory will create repeated waste?
If the answer is “everywhere”, account-level scope may be justified. If the answer is “only here”, keep it inside the PMax campaign. When the answer is uncertain, local scope is the safer first move because you can review its effect without changing the behaviour of unrelated campaigns.
The Close Variants Trap and Brand Exclusions
A negative keyword isn't a semantic veto. Google can match it according to the negative match type you select, but negative keywords don't automatically cover every phrase with similar intent. Excluding “cheap running shoes” won't necessarily exclude “affordable trainers” or “budget sneakers”. Those queries may express the same commercial concern while using entirely different wording.
Google's help content also warns that negative keywords don't match close variants in Performance Max. That creates a common failure pattern: an advertiser sees one unwanted query, adds the exact wording, then assumes the entire intent cluster is gone. Spend continues under different language, while the exclusion list gives a false sense of control.
Test clusters, not assumptions
Use small batches built around a clearly defined theme. Add a limited group of related terms, then monitor Search terms and campaign diagnostics before expanding the cluster. The point isn't to wait for a perfect statistical experiment. It's to preserve enough traceability that you can identify which batch caused a relevant query to disappear.
Avoid uploading hundreds of unreviewed negatives at once. If conversions fall afterwards, you won't know whether the issue came from a broad match choice, a product term, a brand variation or an innocent-looking support phrase. A dated change log with the exact terms, scope and reason is more valuable than a large list no one can interpret.
Testing principle: If you can't explain which exclusion caused a change, you added too many exclusions in one pass.
Brand protection needs separate handling. Google says brand exclusions are preferable when the objective is to block your own brand variants, because exclusions can catch misspellings and foreign-script variants that negative keywords may miss. Review the campaign's brand settings rather than trying to force every brand-control requirement into a negative list.
That distinction matters when competitor names appear in Search terms. A competitor query can be a deliberate strategic choice, an accidental match or a sign that the campaign's product and landing-page signals are too broad. The appropriate response may be a campaign-level exclusion, a brand setting or a broader review of assets and URL expansion. Performance Max brand leakage guidance provides a useful prompt for that audit.
Building Tiered Reusable Negative Lists
A negative keyword library should work like organised content management, not a junk drawer. Without tiers, teams duplicate universal terms across campaigns, consume list capacity and make it difficult for the next buyer to understand why a query was blocked.
The structure I recommend starts with a small universal layer. This contains terms that no campaign should use under the current business brief, such as clearly irrelevant employment intent or explicitly prohibited competitor activity. It shouldn't become a dumping ground for every query that failed to convert.
The next layer groups intent by vertical or audience. An apparel retailer may need one group for irrelevant product conditions, while a B2B advertiser may need another for consumer, student or job-seeker themes. These lists should be reusable, but only across campaigns that share the same commercial logic.
The final layer belongs to the individual campaign. It covers seasonal offers, discontinued ranges, location restrictions, margin constraints or a particular asset group. Local experimentation belongs.
A naming system prevents scope mistakes
Use names that reveal both level and intent. For example:
- A1-Universal: Account-wide terms approved for every campaign.
- A2-Apparel-Intent: Reusable exclusions for relevant apparel campaigns.
- C3-SpringSale-2026: Local terms linked to one time-bound campaign.
The exact naming convention matters less than consistency. A buyer should know the expected scope before opening the list.
Google's support documentation confirms that campaign-level PMax negatives can hold up to 10,000 keywords per campaign, while account-level exclusions hold up to 1,000 terms. Large UK ecommerce accounts should therefore avoid filling campaign capacity with repeated universal terms. Put shared exclusions in the governed account layer and reserve campaign space for distinctions that matter.
Governance note: Every list needs an owner, a reason for existence and a review date.
Maintain a register alongside Google Ads. Record the term, match type, scope, date added, approving person and reason. Prune duplicates and outdated seasonal exclusions during scheduled audits. This makes new campaign launches faster and reduces the chance that a junior buyer applies a list because its name sounds relevant.
Maintenance Checklist and When to Revisit
PMax clean-up isn't a one-off upload. Query behaviour changes when products, assets, feeds, landing pages and offers change, so the negative keyword strategy needs an operating rhythm.
A weekly review can be short if it stays focused. Scan new Search terms, flag obvious intent mismatches and inspect whether an existing exclusion is being bypassed through different wording. Don't turn every unusual query into a permanent rule. Classify it first, then decide whether the issue is universal, vertical-specific or campaign-specific.
The operating checklist
- Weekly Search terms review: Look for new job, support, DIY, freebie, competitor and product-condition patterns. Add only exclusions with a clear business rationale.
- Monthly list audit: Compare reusable lists with new products, discontinued ranges, seasonal offers and changed margins. Remove terms that no longer reflect the account.
- Quarterly governance check: Review account-level exclusions against every Search, Shopping and PMax campaign. Check for cross-campaign bleed and confirm that each global term remains defensible.
- Campaign launch review: Before enabling a new PMax campaign, check its inherited lists and add the local exclusions required by its product or service scope.
Three signals should trigger a deeper review. First, cost per conversion is rising while impressions remain broadly flat, which can indicate that the campaign is reaching less relevant intent rather than lacking volume. Second, brand terms continue appearing in PMax Search terms after campaign-level negatives have been added, which suggests a scope, variant or brand-exclusion issue. Third, a campaign-level list is approaching the 10,000-keyword limit, documented in Google's Performance Max support content, which is a sign to consolidate intent clusters and remove duplication.
PMax optimisation compounds through repeated observation, not a single aggressive intervention. Document every change with its date and reason, review conversion impact after each batch and resist the urge to treat the largest possible exclusion list as the most effective one.
PPC Geeks provides Google Ads account audits, campaign management, feed optimisation and ongoing strategic reviews for UK SMEs and ecommerce advertisers dealing with complex paid-search activity. If your PMax account needs a scope decision, search-term clean-up or a documented negative-keyword governance system, visit PPC Geeks to discuss the account with its PPC team.
