If your team is reviewing September migration notices, the first task is identifying which legacy settings each campaign actually uses. The official documentation is contradictory. The top of the page says one thing, while a small update notice says another. You need to know exactly which campaigns will change so you can protect your ROAS and maintain coverage for your high-volume SKUs before the holiday shopping season begins. Misunderstanding the timeline means you might pause the wrong campaigns, misallocate your Q4 budget, or waste hours trying to fix a setup that was never broken.

The confusion comes from a mid-year update that split the migration timeline. Retailers need to separate their Automatically Created Assets and campaign-level broad match settings from their Dynamic Search Ads.

The June correction separates DSA from broad match

According to a June 11 correction to Google's original announcement, the Dynamic Search Ads sunset and auto-upgrade is delayed until February 2027. However, campaigns using Automatically Created Assets and the campaign-level broad match setting will still begin their upgrade to AI Max in September 2026.

Many operators read the old page summary or later paragraphs that retain the superseded DSA September wording. The explicit June correction governs the actual timeline. The revised DSA migration window begins in February 2027. Check campaign-specific notices and any other enabled legacy features rather than treating the campaign label as a blanket exemption from change.

This delay is a significant operational reprieve. Dynamic Search Ads are often the catch-all net for large catalogs, picking up traffic for SKUs that lack dedicated keyword coverage. Use the additional preparation time to record the role of each DSA campaign, its important destinations and the controls you will need to verify before migrating. Keep monitoring account notices during Q4. A revised migration date is a planning input, not a guarantee that nothing else in the account will change.

You also need to distinguish between broad-match keywords and the campaign-level setting. Having broad-match keywords in an ad group does not prove a campaign is eligible for the September upgrade. The campaign-level setting is a relevant September trigger; Automatically Created Assets are another. Broad-match keyword presence alone does not establish either condition.

Consider a hypothetical example. You run two Search campaigns for a new line of hiking jackets. Campaign A uses exact and phrase match keywords, but you recently added a few broad-match keywords to capture long-tail queries. Campaign B has the campaign-level broad match setting enabled. Campaign A needs a separate check for ACA and any migration notice; those broad-match keywords alone do not determine its status. Campaign B has one of the relevant legacy settings. Record the distinction before making a change to either campaign.

The upcoming language targeting shift

Another variable hits your Search campaigns this month. Effective late September 2026, Google is changing how language targeting works. According to the upcoming language targeting changes, Search and AI Max Search campaign language settings are being removed. Instead, the language of your ads will inform the matching process.

This upcoming change requires a review of your ad copy and the entire ad-to-page journey. Review ad and landing-page language together with the market you can actually serve. Ad language informs matching, but it is not a promise that every buyer has the same language preference. A mismatch can make the journey harder to understand, so sample the complete path rather than relying on one setting.

This update also impacts how your technical team interacts with the platform. If your team uses scripts or API tools to update language criteria on Search campaigns, those mutations will return an error starting in late September. Performance Max Search changes similarly, but other PMax channels retain campaign language targeting and do not face the same API error rule.

The API error rule for language mutations is a quiet trap for technical marketing teams. Many large stores use automated scripts to adjust bids and settings across hundreds of campaigns based on inventory levels or regional performance. If your script attempts to update a language setting on a Search campaign after late September, the resulting error could halt the entire script. This means your bid adjustments or budget reallocations might fail silently. Ask developers to handle Search campaign language mutations according to the new API guidance. Do not apply the same removal indiscriminately to Performance Max: its campaign-level language setting remains relevant on other channels, and the announcement explicitly distinguishes its API behavior.

Building a migration baseline for your catalog

When performance fluctuates in late September, you need to know if it was caused by an AI Max upgrade, a language setting removal, or standard auction pressure. You cannot attribute all performance changes to the migration.

Build a strict baseline for your account. Document your campaign types, their current settings, the assigned owner, and the exact date any changes occur. If a campaign upgrades to AI Max on a Tuesday, note that date in your tracking document. If you see a drop in efficiency the following week, you can diagnose soft ROAS by looking at the specific timeline of platform changes versus feed health or creative fatigue.

This documentation prevents panic. When a stakeholder asks why a specific product category is seeing higher cost per click, you can point to the baseline. You will know which change notices and actual settings changes need investigation, without assuming that a DSA campaign is otherwise untouched until 2027. Assign a specific media buyer to own this tracking document so there is a clear line of accountability.

What good looks like

Managing platform migrations at catalog scale requires discipline. Here is how lean ecommerce teams handle the September updates:

  • Filter your account for campaigns using the campaign-level broad match setting to identify immediate upgrade candidates.
  • Record February 2027 as the revised DSA migration start and check other legacy settings separately.
  • Separate broad-match keyword campaigns from campaign-level broad match campaigns in your internal reporting.
  • Review your API scripts to ensure they do not attempt to mutate Search campaign language settings after late September.
  • Document the specific ad languages used in your Search campaigns, as these will inform matching going forward.
  • Record baseline ROAS and conversion volume for all upgrading campaigns before the transition begins.
  • Add a column to your lean monitoring checklist to track the exact date each campaign transitions.