Performance Max campaigns spend wherever Google's models decide, and for the first two years of the format the only way to tell them "not that search" was to file a form and wait for a Google rep. That era is over: campaign-level negative keywords are now a self-serve setting in every account, and they're the single highest-leverage control PMax gives you. This is the exact path to add them, the limits that apply, and — just as important — the two things negative keywords in PMax quietly don't do.
What changed, and when
Google began rolling out self-serve campaign-level negative keywords for Performance Max in December 2024, and the feature reached general availability in early 2025. The original cap was a token 100 keywords per campaign; in March 2025 the limit rose to 10,000 negative keywords per campaign — the same ceiling as Search campaigns, and effectively unlimited for most advertisers. If your PMax playbook still says "request negatives through your Google rep," it's two years stale.
The exact steps
In the current interface: open Audiences, keywords, and content → Keywords in the left navigation, select the Performance Max campaign, click + Negative keywords, enter one keyword per line, and save. You can also reach the same setting from the campaign's own Settings panel, where a dedicated negative keywords section appears. Bulk entry works by pasting a list; there's no editor-style upload flow, but at one keyword per line you can move hundreds in a single paste.
The account-level layer
Campaign negatives aren't the only layer. Account-level negative keywords — up to 1,000, set under account settings — apply automatically across Search, Shopping, and Performance Max. That's the right home for the exclusions that should never show anywhere: job-seeker terms ("careers," "salary"), free-hunter terms, adult-adjacent brand collisions. One caveat that surprises people migrating from Search: shared negative keyword lists still can't be attached to PMax campaigns. The 1,000 account-level slots and the per-campaign entries are the only two mechanisms; plan the split accordingly — universal exclusions at the account, campaign-specific ones per campaign.
What PMax negatives don't block
Two pieces of fine print determine whether your exclusions actually work. First, negative keywords in Performance Max apply only to Search and Shopping inventory — they do nothing on YouTube, Display, Discover, or Gmail placements. Junk video placements need placement exclusions (or an exclusion request at the account level), not negatives. Second, negative keywords don't expand to synonyms or close variants the way positive broad match does: excluding "cheap" does not exclude "cheapest" or "affordable." Every variant you want blocked must be entered explicitly — which is exactly why the 10,000-keyword ceiling matters.
Where to find the terms worth excluding
PMax's search terms insights (under Insights & Reports) finally show enough query-level data to mine: sort by spend, scan for intent mismatches, and move anything irrelevant into the negatives the same day. Pair negatives with the format's other two exclusion controls — brand exclusions for competitor names you don't want to pay for (or your own brand, if you want PMax forced to hunt net-new demand), and placement exclusions for the app and site inventory that pads Display reach. The three controls cover different inventory; using only negatives leaves two-thirds of the waste untouched.
Make it a cadence, not a cleanup
The accounts that get value from this treat negatives as a weekly fifteen-minute ritual: pull search terms insights, add the misses, log the change. The ones that don't treat it as a one-time cleanup, and six months later the campaign has drifted back to spending on other people's brand names and "free template" queries. Precision targeting is a habit, not a setting — the same discipline we described for income-based targeting in standard Google Ads applies doubly to a format that makes its own decisions. If nobody has looked at your PMax search terms since the campaign launched, that review is a fifteen-minute job with a measurable payback.