What Is Actually Changing

Google blocked advertisers from creating new campaign-level Broad Match and legacy Automatically Created Assets configurations back on August 3, 2026. Now, between September 1 and 30, it's converting every existing campaign still running those settings into AI Max, rolling the change out progressively rather than all at once. A second wave targeting Dynamic Search Ads campaigns is scheduled for February 2027. Google says the change delivers an average of 7% more conversions. Independent tests across more than 250 retail campaigns tell a different story, some advertisers measured a ROAS drop of up to 35% after the same kind of automated upgrade.

That gap between Google's claimed lift and what advertisers are actually measuring is the real story here. AI Max campaigns behave differently by default: search term matching is switched on automatically, while text customization and final URL expansion settings vary depending on which legacy feature you're migrating from. If nobody on your team reviews the new defaults, your campaign could start bidding on and rewriting ads for search terms and destinations you never approved.

What to Do Before It Hits Your Account

  • Audit which campaigns are still on legacy settings. Check every active Search campaign for campaign-level Broad Match or standalone Automatically Created Assets. Anything still using them will be migrated this month whether you're ready or not.
  • Use Google's new migration timestamp fields. The campaign.aca_migration_date_time and campaign.broad_match_migration_date_time fields tell you exactly when a given campaign was converted, so you can isolate the before-and-after performance instead of guessing which week the numbers shifted.
  • Benchmark performance now, not after Q4 starts. With the migration landing right before the holiday shopping season, waiting until October to notice a ROAS drop is the expensive way to find out. Pull baseline numbers this week so you have something to compare against.
The Real Takeaway

A mandatory migration with no opt-out means the choice isn't whether you move to AI Max, it's whether you control the terms. Advertisers who restructure their campaigns ahead of Google's timeline keep some say over targeting and creative; the ones who wait get whatever defaults Google assigns, right as budgets tighten for the year's biggest quarter.

Getting Ahead of It

You don't need to overhaul your entire account this week. Start with your highest-spend campaigns, confirm whether they're still on legacy settings, and set a review date once the migration timestamp shows up. That's a manageable first step toward making sure an automatic platform change doesn't quietly eat into your ad budget during the most competitive quarter of the year.