Google published the technical mechanics of its September migration on August 12, 2026, confirming that creation of legacy campaign-level broad match and automatically created assets configurations was switched off nine days earlier and that the automated upgrade will run across the whole of September.

The post appeared on the Google Ads Developer Blog under the name of Bob Hancock of the Google Ads API Team. It arrived one week after advertisers received an email notice of the same migration, and it supplies the detail that email did not: exact default settings for each affected cohort, two new reporting fields, a hard block on legacy creation already in force, and a grace period for older API versions that runs into 2027.

Two phases now govern what Google calls the legacy automigrations. Phase 1 covers campaign-level broad match and standalone automatically created assets, and begins September 1, 2026. Phase 2 covers Dynamic Search Ads and has been rescheduled to February 2027.

A migration that runs for a month, not a day

The September 1 date has been reported as a switch. According to the developer post, it is closer to a window. The migration job will roll out progressively throughout the month, meaning a campaign that has not changed on September 2 may still change on September 24.

That progressive rollout creates a reporting problem, and Google has addressed it with two new fields on the campaign resource. Advertisers and developers can query campaign.aca_migration_date_time and campaign.broad_match_migration_date_time to identify which campaigns have been migrated at any point during the month. The sample query published with the post filters both fields against a Unix epoch timestamp, returning campaign identifier, campaign name, and the two migration timestamps.

For anyone running before-and-after performance comparisons, those timestamps are the only precise marker of when a given campaign's targeting behaviour changed. Aggregate month-level analysis will blend pre-migration and post-migration traffic in unpredictable proportions.

Default settings differ by cohort

Google states that campaigns will be migrated in-place to equivalent AI Max settings, a design intended to support campaign management continuity and minimise performance volatility. The equivalence is not identical across the two affected groups.

Campaigns using campaign-level broad match receive text customization set to opt out, final URL expansion set to opt out, and search term matching set to true by default. Existing brand inclusion and exclusion lists are preserved and moved into the new setup in place.

Campaigns using standalone automatically created assets receive text customization set to opt in by default, final URL expansion set to opt out, and search term matching set to true by default.

The asymmetry matters. Automatically created assets governed creative generation. Search term matching governs which queries an advertisement becomes eligible to serve against. A campaign that opted only into automated headline and description writing inherits automated query expansion by default under the new configuration, a change already flagged in coverage of the August 5 email notice. The developer post confirms the same defaults at API level and adds the final URL expansion status, which is off for both groups. Because final URL expansion depends on text customization being active, landing page rerouting does not apply automatically to either cohort at migration.

Creation was blocked on August 3

The most concrete new fact in the August 12 post is dated earlier. Google describes a legacy creation end of life on August 3, 2026: creating new campaign-level broad match configurations or legacy automatically created assets is blocked across the user interface, Google Ads Editor, and all versions of the API.

That block was already in force when the post appeared. It was in force when the August 5 email went out, and the email did not mention it. Agencies onboarding new accounts during the first fortnight of August would have encountered the block without documentation explaining it.

Google frames the enforcement as a measure to prevent the creation of new legacy structures ahead of the auto-migration. The practical effect is that the affected population is now fixed. No account can add to it.

Older API versions get thirteen months

The third section of the post sets out an API versioning lifecycle that separates what happens to campaigns from what happens to code.

Any new versions of the Google Ads API released after September 1, 2026 will completely remove the legacy entities used to create or manage campaign-level broad match settings and automatically created assets. Previously released versions that are currently active will temporarily continue to support both legacy setups.

The sunset timeline is tied to the standard version lifecycle rather than to the migration. Editing and managing legacy setups remains possible through older API versions until those specific versions reach their scheduled sunset, typically one year after introduction, which Google places at around September 2027. At that point all remaining legacy entities are permanently removed.

That schedule sits inside the release cadence Google adopted when it moved the API to monthly releases from January 2026, lifting major versions from three to four a year while extending support to twelve months. Version 25 arrived on July 22, 2026 and removed two lifecycle goal resources outright, a reminder that major releases are where breaking changes live. Under the twelve-month rule, a version released in September 2026 would be supported into September 2027. The legacy entities and the versions that carry them expire together.

Google's developer action plan asks integrators to audit scripts, external tools, and client libraries still attempting to create or edit campaign-level broad match settings or legacy automatically created assets, to move campaign construction workflows to standard Search campaigns using the AI Max settings bundle, and to handle grandfathered read-only entities. On that last point the post is specific: integrations attempting to modify, rather than pause or delete, legacy expanded dynamic search ads or criteria once they transition to standard ad groups will encounter API error codes.

What the broad match setting does

Google's help documentation, updated for the migration, describes the feature being retired in plain terms. According to the help page, "the broad match campaign setting enables Search campaigns to exclusively use broad match as the keyword match type." Enabling it converts all existing phrase and exact match keywords into broad match and ensures all keywords added also use broad match. The setting is available only to campaigns using conversion-based Smart Bidding.

The documentation also sets out how the setting interacts with keyword prioritisation inside an account, a four-tier hierarchy that survives the migration. Exact match keywords identical to the search term rank first. Phrase and broad match keywords, or Performance Max search themes identical to the search term, rank second. Artificial intelligence based relevance ranking comes third, selecting only the most relevant keywords from the most relevant ad groups. Ad Rank breaks ties at the fourth tier.

Keywords in a campaign carrying the setting are prioritised as if both a broad match and an exact match version of the keyword were present. Where the same keyword exists in exact match in a separate campaign, the version with the higher Ad Rank goes to auction. The help page carries a notice that campaigns using the setting will automatically be upgraded to AI Max from September 2026.

A separate Google help document covering account level automated assets describes a different set of formats that operates at account rather than campaign level, including dynamic sitelinks, dynamic structured snippets, automated location assets, seller ratings, dynamic callouts, dynamic business information, dynamic image assets, and site visits. According to that documentation, Google Ads charges for no more than two clicks per impression on each ad and its assets, with clicks on seller ratings exempt from charges. Those formats are not part of the September migration, which addresses campaign-level constructs.

The Dynamic Search Ads timeline moved again

Phase 2 carries the more interesting revision. Active legacy DSA campaigns are excluded from the September automigrations and continue to serve as normal. The August 12 post then restates the DSA timeline in terms that differ from the version published on June 11, 2026.

The June post set out four stages: creation restored immediately, an extended testing period from June 2026 to January 2027, removal of the ability to create DSAs in January 2027, and automigration beginning February 2027, at which point remaining active DSA campaigns would be automatically upgraded to Performance Max or AI-powered Search campaigns.

The August post replaces that sequence. September 2026 brings in-account pre-migration banners in the interface to warn unmigrated advertisers and encourage voluntary one-click upgrades through a setting Google labels "Upgrade Your Dynamic Search Ads (DSAs) to AI Max" under Campaign Settings. January 15, 2027 brings an official reminder notification to all impacted accounts. Automigration runs from February 1 to February 28, 2027, and it is during that window that the ability to create new DSA ad groups is permanently removed.

Two changes are embedded in that restatement. Creation removal has moved from January 2027 into the February automigration window, extending the build period by up to six weeks. And the destination has narrowed: where the June post named Performance Max or AI-powered Search campaigns, the August post states that unmigrated DSA campaigns will automatically upgrade to standard Search ad groups with AI Max enabled. Performance Max is no longer mentioned as an outcome.

Neither change was flagged as a change. Both appear inside a section presented as preparation guidance.

Context for the migration

The original schedule was published on April 15, 2026 by Brandon Ervin, Director of Product Management at Google Ads, in the announcement that declared AI Max out of beta and put all three legacy settings on a September track. One of the three subsequently escaped that date. Two did not.

AI Max itself was announced on May 6, 2025, with an implementation guide published later that month claiming 14% more conversions or conversion value at a similar cost per acquisition or return on ad spend target, rising to 27% for campaigns still mostly using exact and phrase keywords. By April 2026 the headline figure had been revised to an average of 7% more conversions when the full feature suite runs together, compared with search term matching alone.

Independent measurement has been less flattering. Testing documented in August 2025 found 99% of impressions produced zero conversions across roughly 30,000 search terms. A larger study covering more than 250 retail campaigns published in November 2025 found conversions delivered at approximately 35% lower return on ad spend against traditional match types. On August 12, 2026, the same day as the developer post, invalid traffic detection company Lunio published a retail study covering more than 414 million clicks recorded between October 2025 and June 2026, reporting that retail search campaigns running AI Max were exposed to 72% more invalid traffic than search campaigns without it, and that AI Max accounted for 68% of invalid clicks detected across its Google search dataset.

Google has continued extending the framework in parallel. AI Max reached Shopping campaigns on April 30, 2026 and travel formats in the same period. Reporting for the format expanded with new expanded match and expanded landing page metrics in 2025, and the API gained AI Max experiment types in May 2026.

The pattern is recognisable. Google phased out call-only ads on a comparable arc, with creation disabled first and full shutdown scheduled for February 2027. Legacy formats receive a transition window, voluntary tools appear before automatic ones, and creation blocks precede migration. The August 3 block follows that template precisely.

Why this matters for advertisers and developers

The financial exposure is not evenly distributed. Accounts that never enabled either setting are unaffected. Accounts that did face a targeting change of variable magnitude depending on which cohort they fall into, arriving at an unspecified point across thirty days.

For agencies and bid management vendors, the API dimension is the harder constraint. Code that creates campaign-level broad match settings or legacy automatically created assets stopped working on August 3. Code that reads or edits them keeps working until the API version it targets sunsets, around September 2027. Between those two dates sits a maintenance window in which legacy entities exist, remain editable, and cannot be recreated if deleted.

Terms updated in July 2026 made advertiser accountability explicit for content produced by automated systems, including automatically created assets and AI Max text variants. Roughly 70 million creative assets were generated in the fourth quarter of 2025 alone across AI Max and Performance Max campaigns. A migration that switches text customization on by default for one cohort adds to that volume without a corresponding approval step.

Timing compounds the exposure. The September window closes eleven weeks before the fourth-quarter trading peak, leaving a short period in which to measure whether migrated campaigns hold performance parity before budgets concentrate. The two migration timestamp fields are the instrument that makes such measurement possible at all.

Timeline

Summary

Who: Google published the post through the Google Ads Developer Blog under the name of Bob Hancock of the Google Ads API Team. It affects advertisers, agencies, and software vendors operating Search campaigns that use the campaign-level broad match setting or standalone automatically created assets, plus those still running Dynamic Search Ads.

What: Legacy automigrations are split into two phases. Phase 1 upgrades campaign-level broad match and standalone automatically created assets campaigns to AI Max, with search term matching on by default for both, text customization off for the broad match cohort and on for the automatically created assets cohort, and final URL expansion off for both. Brand inclusion and exclusion lists are preserved for the broad match cohort. Creation of new legacy configurations was blocked on August 3, 2026. Two campaign fields report migration timestamps. Phase 2 covers Dynamic Search Ads.

When: The post was published on August 12, 2026. Legacy creation ended August 3, 2026. Phase 1 migration runs September 1 to September 30, 2026. New API versions released after September 1, 2026 remove the legacy entities; older versions retain them until scheduled sunset around September 2027. DSA banners appear in September 2026, reminders on January 15, 2027, and automigration between February 1 and February 28, 2027.

Where: The changes apply to Google Ads accounts globally, enforced across the Google Ads interface, Google Ads Editor, and all versions of the Google Ads API.

Why: Google states that campaigns are migrated in-place to equivalent AI Max settings to support campaign management continuity and minimise performance volatility, and that creation blocks prevent new legacy structures forming ahead of the automated upgrade. The migration consolidates separate legacy targeting and creative features into a single AI Max settings bundle across Search campaigns.