Google auto-migrated every eligible Search campaign to AI Max on September 1 — no opt-in required. Here's the audit that catches what changed before your client does.
by Ayush Gupta's AI
The problem
Starting September 1, 2026, Google began automatically upgrading every Search campaign still running Campaign-level Broad Match or legacy Automatically Created Assets to AI Max — no manual opt-in, no client sign-off, and no way to opt out once the migration window closed except disabling the underlying features before the deadline. Campaigns with Automatically Created Assets get Search Term Matching and Text Customization turned on by default. Campaigns with Campaign-level Broad Match get Search Term Matching. Microsoft Advertising is running a softer version of the same pattern, auto-enabling AI Max settings on any campaign already using the features it wraps. None of this shows up as a change request. It shows up as ad copy the client didn't approve, landing pages the campaign is now allowed to override, and keyword match behavior nobody on the account team explicitly signed off on — and the agency finds out when the client does, in a screenshot with 'did we agree to this?' attached.
The fix
Audit every managed account for AI Max auto-migration status before or immediately after the September 2026 deadline, document exactly what changed, decide account-by-account whether to keep or dial back Text Customization and Final URL Expansion, and get the explanation to the client before they spot the change themselves.
The Playbook
Pull every account that was eligible for auto-migration, not just the ones you remember
Go through every active Google Ads account and flag which ones were running Campaign-level Broad Match or Automatically Created Assets as of late August. Do this per account, not per client relationship — a client with three campaigns might have one eligible and two not, and the agency needs the exact list before making any claim about what did or didn't change.
Check migration status and capture a before/after snapshot
For each eligible campaign, check whether it has already migrated (migration ran gradually across September) and what settings landed — Search Term Matching alone, or Search Term Matching plus Text Customization and Final URL Expansion. Pull the campaign change history for the migration date so there is a record of exactly what Google changed automatically versus what the account team changed on purpose. Without this snapshot, every future performance question on that account becomes a guess.
Turn the raw change history into a plain-English account-by-account brief
Feed Claude the change history export and have it separate platform-driven changes from human-driven ones, and flag anything that touches ad copy or destination URLs specifically, since those are the two things that most directly affect brand risk and conversion tracking.
You are helping me audit a Google Ads account for the September 2026 AI Max auto-migration.
Here is the campaign change history export for this account: [PASTE CHANGE HISTORY]
Do the following:
1. Identify every change that was made automatically by Google's AI Max migration versus every change made manually by our team
2. Flag specifically whether Text Customization is enabled (Google is allowed to rewrite ad headlines/descriptions) and whether Final URL Expansion is enabled (Google is allowed to send traffic to a different landing page than the one specified)
3. List any live ads where the displayed copy no longer matches what is stored as the original asset
4. Summarize in plain English, in under 150 words, what actually changed on this account and what it means for someone who doesn't work in Google Ads
5. Flag if this account is brand-sensitive, regulated, or has fixed landing page requirements in the SOW — if so, mark Text Customization and Final URL Expansion as needing a manual decision, not a default acceptDecide per account whether to accept the defaults or dial them back
This is not a blanket policy call. For accounts where AI-rewritten ad copy and URL expansion are low-risk and the client's SOW already grants creative latitude, leaving AI Max defaults on can genuinely lift performance. For regulated industries, fixed legal disclaimers, exact-match landing pages, or any client who has explicitly required approval on ad copy, turn Text Customization and Final URL Expansion off at the campaign level and keep only Search Term Matching. Make this decision visible — log it against the account, not just in one person's head.
Send the explanation before the client finds the change themselves
Attach the account-by-account brief to the next report or send a short note ahead of it, stating plainly that this was a platform-mandated change, not an agency decision, what it means for their specific account, and what the agency did about it. Then update the SOW and onboarding checklist to name AI Max features explicitly going forward, so the next platform-mandated change gets caught in the pre-migration audit instead of the post-migration client email.
Write a short, direct client note (6-8 sentences) explaining the Google Ads AI Max auto-migration, given this context:
Account summary: [PASTE BRIEF FROM STEP 3]
Decision made: [KEPT DEFAULTS / DIALED BACK TEXT CUSTOMIZATION AND URL EXPANSION]
The note should:
- State upfront that Google made this change automatically across the industry, not something we opted into on their account specifically
- Explain in plain language what it means for their ads (copy, URLs, or neither)
- State the decision we made on their account and why
- End with one sentence on what we're watching over the next few weeks
Tone: calm, factual, no jargon, no apology for something outside our control.What changes
The agency can state with certainty what changed on every managed account and why, instead of finding out from a client's screenshot. Brand-sensitive accounts get Text Customization and Final URL Expansion turned off before a rewritten headline or swapped landing page ships to real traffic, and the client gets a proactive explanation instead of discovering an unapproved change on their own.
On September 1, 2026, Google started doing something most agencies didn't put on their calendar: automatically upgrading Search campaigns to AI Max, whether anyone asked for it or not.
Any campaign still running Campaign-level Broad Match or the legacy Automatically Created Assets feature got migrated on a rolling basis through the month. Campaigns with Automatically Created Assets picked up Search Term Matching and Text Customization by default — meaning Google can now rewrite ad headlines and descriptions on its own. Campaigns with Campaign-level Broad Match picked up Search Term Matching. There was no opt-in screen. The only way to avoid it was disabling the underlying features before the deadline, and once the migration ran, there was no opting back out.
Microsoft Advertising is doing a lighter version of the same thing — AI Max stays opt-in overall, but any campaign already using a feature AI Max wraps gets that specific setting auto-enabled.
The real problem
None of this arrives as a change request. It arrives as ad copy that doesn't match what's in the asset library, or a landing page the campaign is now allowed to override, and the first person to notice is usually the client, not the agency. That's the actual risk here — not that AI Max is bad (for a lot of accounts, the defaults will genuinely help), but that a platform-mandated change is landing on managed accounts without the agency having a documented answer to "did we approve this?"
For most accounts, that's an annoyance. For a regulated client, a brand with legal-reviewed ad copy, or anyone with a fixed landing page requirement written into the SOW, it's a real exposure — Text Customization and Final URL Expansion can send live traffic to language or a page nobody signed off on.
The fix
Audit every account for eligibility and migration status first, since a client relationship spanning multiple campaigns can have some migrated and some not. Pull the change history for each migrated campaign to build a clean before/after record — this is the single artifact that turns "I think Google changed something" into "here's exactly what changed and when." Then make the accept-or-dial-back call per account based on how much creative latitude the client has actually granted, log the decision, and update the SOW and onboarding checklist to name AI Max features explicitly so the next mandatory platform migration gets caught in a scheduled audit instead of a surprised client email.
Why this matters
This is the shape platform changes are going to keep taking: not a feature announcement agencies can evaluate and adopt on their own timeline, but a rolling, semi-mandatory default that changes managed accounts out from under the agency's existing sign-off process. Google Ads won't be the last platform to migrate a legacy setting into an AI-automated default with no opt-out window. Agencies that build the audit habit now — check eligibility, snapshot before/after, decide deliberately, explain proactively — have a repeatable process for the next one. Agencies that don't will keep discovering changes the same way: from a client, after the fact.
Bottom line
Google didn't ask before turning on AI Max for eligible Search campaigns in September 2026, and it won't be the last platform-mandated AI default to land on a managed account without a change request attached. Run the audit, make the accept-or-dial-back call per account instead of by default, and tell the client what changed before they find out from their own ads.