Review the Changes Advertisers Should Check in Microsoft Advertising's September 2026 Update

What is in this update?

The date checked is 2026-10-08. The announcement says nothing about price or cost changes.

How did the SOAP shutdown schedule change?

The plan first announced in April, to offer new features only in REST from October 1, 2026, has been extended. New features will be available in both SOAP and REST until January 31, 2027, and SOAP will be fully shut down on that date. SDK users should follow the SDK migration documentation, and if you do not use an SDK, you need to switch to the REST URLs and request format.

First check whether any external tools or in-house scripts connected to your account use SOAP. If you use an agency or a solution provider, it is safer to ask about their REST migration schedule.

What are the conditions for the HubSpot integration and LinkedIn lists?

Advertisers who use HubSpot can build audiences from CRM contacts across Microsoft surfaces such as Bing, Copilot, Outlook and Xbox. Use comes with subscription plan and access permission conditions, and the details must be checked in HubSpot's documentation.

LinkedIn company lists are created in campaign settings or the audience library and used for LinkedIn profile targeting in Search and Audience campaigns. Company names are mostly displayed in English, and the announcement says consumer data from users in the EEA, the UK and Switzerland is excluded.

How do you use optimization experiments?

It is a feature for comparing settings such as bidding, targeting and creative in a controlled A/B test. You compare the results with the original setup on a unified page, and you can apply the winning change to the existing campaign or turn it into a new campaign. The announcement does not describe the statistical method or the decision criteria used. So you need to set your own operating rules, such as changing only one variable at a time and allowing enough time. You cannot assume the results always lead to improvement.

For experiments, it is less risky to work out your procedure on a small campaign rather than a large-budget one, and then expand.

Where can you check?

You can check supported markets and conditions through the official Microsoft Advertising blog, in-account Help and your account team. Feature scope and schedules can change, so look at the latest guidance again before you apply anything.