Google Ads AI Max Migration Has Started: What Business Advertisers Should Do Now

If your business runs ads on Google, September is a month to pay attention. On 1 September 2026 Google began automatically migrating Search campaigns that use campaign-level broad match or automatically created assets over to AI Max, its AI-driven campaign framework. There is no opt-out, there is no rollback, and the change does not land on a single day. Campaigns are being moved progressively throughout the month, which means yours might change tomorrow, or in three weeks, without you touching anything.

The writing has been on the wall for a while. Google stopped letting advertisers create new campaign-level broad match settings back on 3 August, and only announced it publicly two days later, after some agencies had already run into the block mid-onboarding. Dynamic Search Ads get the same treatment in February 2027. By this time next year, the legacy way of running Search campaigns will simply not exist.

For business owners and marketing managers, the practical question is not whether to accept the change. That decision has been made for you. The question is what the Google Ads AI Max migration will actually do to your account, and what you should check before the Q4 trading season arrives. Let's sink in.

What the AI Max migration changes this September

The September migration covers two legacy features: campaign-level broad match and standalone automatically created assets. Between 1 and 30 September, every Search campaign still using either of them is being upgraded to AI Max with what Google calls equivalent settings. The rollout is gradual, so two campaigns in the same account can migrate on different days.

Google has added two reporting fields to help you see when it happened, one for broad match migrations and one for automatically created assets. If you work with an agency or an in-house team, it is worth asking them to log those dates, because you will want a clean before-and-after line in your reports.

Dynamic Search Ads were originally supposed to move at the same time, but Google pushed that phase to February 2027 and changed the destination along the way. DSA campaigns will now become standard Search ad groups with AI Max enabled, rather than being folded into Performance Max as first announced. From September 2026 a one-click voluntary upgrade appears in accounts, and from February the migration becomes automatic there too.

What AI Max actually does to your campaigns

AI Max is best understood as three switches bolted onto a Search campaign. Search term matching lets Google expand your reach beyond your chosen keywords, using AI to decide which queries are close enough to your intent. Text customization lets Google rewrite parts of your ad copy based on your landing page content and the search context. Final URL expansion lets Google send clicks to pages on your site that you did not explicitly advertise.

The migration defaults matter here, and they differ by feature. Campaigns coming from campaign-level broad match arrive with search term matching switched on, while text customization and URL expansion stay off. Campaigns coming from automatically created assets arrive with both search term matching and text customization enabled, which is a real change in behaviour, because Google will now be writing ad text on your behalf by default.

Brand inclusion and exclusion lists carry over intact in both cases, which is genuinely helpful. Still, the safe assumption is that after migration your campaigns will match against a wider set of queries than before, and in some cases show copy you never wrote.

Google's numbers against everyone else's

Google's pitch for AI Max is a 7% conversion lift at similar cost per acquisition, measured on accounts using the full feature suite with enough data volume. That number is not invented, but it describes a best case, and the independent testing that has accumulated over the past year tells a rougher story.

A November 2025 study across more than 250 retail campaigns found AI Max delivering roughly 35% lower return on ad spend than traditional match types. Earlier testing from August 2025 found that across about 30,000 expanded search terms, 99% of impressions produced no conversions at all. And a large retail analysis covering 414 million clicks between October 2025 and June 2026 reported 72% more invalid traffic on AI Max campaigns than on comparable campaigns without it.

None of this means AI Max will hurt your account specifically. Results vary a lot by industry, budget and data quality. But the gap between the platform's claim and the independent numbers is wide enough that you should treat the migration as something to measure, not something to trust. The timing adds pressure too, since the September window closes only about eleven weeks before peak Q4 trading.

The controls you keep and the ones you lose

Once a campaign migrates, there is no way back to the legacy setup. You cannot recreate campaign-level broad match, and after February 2027 you will not be able to create new DSA ad groups either. Older versions of the Google Ads API keep limited support for legacy entities until around September 2027, mostly so integrations can pause or remove them, but that is a wind-down, not an escape hatch.

What you keep is more meaningful than it first appears. The individual AI Max switches remain settings you can turn off, so a migrated campaign does not have to keep search term matching enabled forever. Brand lists, negative keywords and audience settings all continue to work. And the new migration timestamp fields give you an exact date to anchor any performance comparison.

The honest summary is that Google has removed the choice of framework, but not yet the choice of behaviour. Whether the switches stay on is still up to you, at least for now.

What to check in your Google Ads account this month

Start with conversion tracking, because everything AI Max does leans on it. If your tracking double-counts, misses phone leads or fires on the wrong page, the AI will optimise toward bad data, and the results tend to be expensive. This is the single highest-value check on the list.

Next, review your negative keyword lists before the expanded matching kicks in. Wider query matching means your ads can surface on searches you never bid on, and negatives are your main fence. Then look at your ad copy and landing pages, since text customization, where enabled, will draw on both. Weak or outdated page content can end up reflected in your ads.

Finally, write down your baseline. Export the last 90 days of performance by campaign, note your migration dates when they appear, and watch the search terms report weekly through October. Small budgets and imprecise tracking are the two conditions under which AI Max tests worst, so if that describes your account, watch it more closely still.

What this means for teams building digital products

There is a quieter lesson in this migration for anyone building websites, apps or SaaS products. With text customization and URL expansion, your landing pages stop being just destinations and become source material for the ads themselves. Page titles, headings and copy quality now feed directly into what Google may show searchers. If your site content is thin or stale, that weakness becomes visible in a new place.

Site structure matters more as well. URL expansion, where enabled, picks pages for you, so orphaned or half-finished pages that were never meant to receive paid traffic can suddenly get it. A tidy sitemap, correct canonical tags and honest page content have shifted from good hygiene into things that protect your ad budget.

For teams that build on the Google Ads API, the deadlines are concrete. Future API versions released after September 2026 drop support for the legacy entities, and the old versions sunset around September 2027. If your product creates or manages Search campaigns for clients, the migration work belongs in this quarter's roadmap, not next year's. This is exactly the kind of plumbing work that is cheap when planned and painful when forced.

Final notes

Forced migrations are never popular, and this one arrives with independent data that openly contradicts the vendor's pitch. Even so, panic is the wrong response. The features AI Max bundles can work well on accounts with clean tracking, healthy budgets and strong landing pages, and the individual controls are still there to be switched off if the numbers turn against you.

Treat September as a measurement exercise. Know your baseline, log your migration dates, keep the switches you did not ask for turned off until you have evidence, and go into Q4 with your eyes open. And if you want help auditing your tracking setup or getting your landing pages into shape before the busy season, that is precisely the sort of work worth doing this month rather than in November.