Google Ads AI Max: the automatic September migration changes how you steer campaigns

From 1 to 30 September 2026, Google is automatically shifting certain Search campaigns to AI Max: no email, no testing period, no action required on your part. Three types of campaigns are affected: those using Automatically Created Assets (now renamed Text Customization), campaign-level Broad Match, or those relying on a target CPA or ROAS inside a budget-limited campaign (a change already rolling out since 17 August). For a Belgian SME running its own Google Ads campaigns, or handing them to an agency, the question is no longer whether AI is making more decisions. It already is. The question is what you actually told it to do.

1. What actually shifts in September

AI Max is built on three features: search term matching (AI widens the reach of your keywords beyond exact matches by reading the context of the query), text customization (headlines and descriptions generated in real time from your site and your assets), and final URL expansion (AI itself picks the most relevant landing page for the query). Campaigns that already used Automatically Created Assets keep text customization active, but also get search term matching switched on, a scope extension most advertisers never explicitly asked for. Dynamic Search Ads, initially targeted by this deadline, have had their migration pushed back to February 2027.

2. The official numbers, and what tempers them

Google cites an average of +14% conversions for advertisers who turn on AI Max, rising to +27% for campaigns that rely mostly on exact and phrase match (Google, April 2026). An independent study covering more than 250 retail campaigns, run by ALM Corp and citing Smarter Ecommerce's analysis, tells a more mixed story: +13% revenue, but also +16% cost per acquisition. More volume, not necessarily more profitability. That gap between the two readings is what should guide the decision to switch each feature on or off, campaign by campaign.

3. What to check before the AI decides for you

Final URL expansion is the riskiest of the three features: without exclusions in place, it can send paid traffic to a blog post, a legal notice page, or a careers page. Text customization, for its part, produces lower-quality ads if you don't supply at least 8 to 10 varied headlines and 3 to 4 descriptions. Before the month is out, an audit is worth doing: list the campaigns affected, export the current setup (keywords, exclusions, landing pages, conversion values), then check the settings actually active after migration rather than assuming them.

The AI angle, human first

AI Max can read more signals, faster, than any team. But the algorithm doesn't know which sale carries margin, which lead will actually close, or which limited creative budget should come first. AI runs the query expansion and the ad generation. Expertise decides the target CPA that matches the business's real economics, sets the necessary exclusions, and checks whether the extra volume is real value or just extra spend.