Google has unleashed the September 2026 spam update — its fourth spam update of the year. The rollout was confirmed by Google, and it lands days after search trackers reported sharp ranking volatility on September 23rd and 24th.

What did Google ship this week?

The confirmed items are straightforward. Google announced the September 2026 spam update, the fourth of 2026. Google Search Console added multimodal search filters to its performance reports. The page experience documentation now includes CrUX ad metrics, though Google says they're not a ranking factor.

There's also regulatory news. The UK's Competition and Markets Authority (CMA) will force Google to make it easier to pick a different default search provider on Android and Chrome. That's a structural change, not a test — it changes how UK users meet search engines in the first place.

The rest of the week sits in test-and-signal territory. Here's the split:

Confirmed by Google: spam update, Search Console filters, CrUX ad metrics in docs, CMA-driven default-search changes, Ads API version 25.2, Merchant Center store ratings requirement updates, and a six-month gun accessories ad pilot in the US.

Spotted in tests or third-party reports: the Discover "Dive deeper" feature, AI Overviews with more external links, AI Overview links pushing users into AI Mode, Local Services Ads redesigns, AI Max reporting and AI Briefs expansion, budget forecast recommendations, advertiser-name sitelinks, Bing's expandable sitelinks, shopping carousel favicons, and Bing testing AI Mode in place of Copilot in search tabs.

Why does the Discover feature worry publishers?

Google Discover is testing a "Dive deeper" feature. It keeps users inside Discover's own experience rather than sending them to publisher sites. If it ships broadly, publishers who depend on Discover traffic could see referral clicks shrink further.

The timing stings. Publishers are already absorbing losses from AI Overviews, and this test adds a second funnel that ends on Google's surface instead of theirs. Takeaway: Discover-reliant sites should watch their referral data closely during this test.

What's changing with AI Overviews and links?

Two signals moved in opposite directions. A report says AI Overviews now show way more external links. That sounds like good news for sites hoping to earn clicks from AI answers.

But there's a catch. Those AI Overviews links reportedly push users into AI Mode rather than to web pages. More links, but the destination may be another Google surface, not your site.

On the ads side, Google is testing Local Services Ads with larger images and a highlights box, AI Max reporting with expanded AI Briefs access, budget change recommendations with forecasts, and sitelinks that display the advertiser name and favicon. Separately, Google Ads will run a six-month pilot for gun accessories ads in the US.

What changed for business and publisher tools?

The small-business side of the week is dense with concrete changes:

• Google Business Profiles now gives businesses four days to reject user-submitted edits.
• Google Business Profiles will email businesses when it detects a spike in spammy reviews.
• Google AdSense dropped its identity verification threshold to $0 — every publisher now verifies identity upfront, not at a payment threshold.
• Google Merchant Center updated its requirements for Store Ratings.
• Google Merchant Center also auto-enabled native checkout, including "Buy on AI Mode and Gemini" — a clear sign of where Google expects commerce queries to go.

For a small publisher, the AdSense change means verification happens at signup, effectively. That's less paperwork later, but it adds friction at the door.

Bing kept pace on the test front. It's trying expandable sitelinks again, adding favicons to shopping carousel ads, and — most notably — testing AI Mode in its search tabs instead of Copilot. That suggests Microsoft may be consolidating its assistant branding around the AI Mode concept.

What should you watch next?

Watch the September spam update's rollout over the next two weeks, track whether the Discover "Dive deeper" test expands beyond its initial scope, and check whether AI Overviews' external links start pointing to real pages rather than AI Mode. Those three signals will shape organic traffic patterns through the rest of the quarter.

By Olivia Hart, SERP Journal