Notification emails and a liaison post surfaced today confirm that Max CPC bidding disappears from new non-portfolio campaigns on October 1, 2026, narrowing the set of routes an advertiser has to a hard cost-per-click ceiling on Microsoft Advertising.

The change reached advertisers through a direct email carrying the subject line "Updates to Max CPC for new campaigns." According to the notification, reproduced in a LinkedIn post published today by freelance Google Adsmanager Joey Bidner, the company wrote that it was informing recipients "about an upcoming change to Max CPC bidding" and that "From 1 October 2026, Max CPC will no longer be available when creating new non-portfolio campaigns."

The date formatting in the notice follows day-month-year convention, which points to a European or United Kingdom localisation of the message rather than the North American variant. October 1, 2026 falls on a Thursday.

The wording attaches the restriction to campaign creation. Advertisers building a new campaign outside a portfolio structure will not find a Max CPC field waiting for them. The visible text of the notice makes no statement about campaigns already running with a Max CPC configured, and neither the email excerpt nor the accompanying commentary addresses whether existing settings persist, migrate, or eventually lapse.

That silence is not a small gap. When Microsoft consolidated its bidding strategies in August 2025, removing Target CPA and Target ROAS as standalone options for newly created campaigns, the company published explicit migration mechanics: campaigns edited through the API, Microsoft Advertising Editor or bulk actions would convert automatically into Maximize Conversions or Maximize Conversion Value with the original target preserved as an optional goal. No equivalent conversion path has been described for Max CPC.

Navah Hopkins, Microsoft Ads Liaison, set out the carve-outs in a LinkedIn post published today. "Target impression share, eCPC, and Portfolio bidding strategies will retain the ability to add a Max CPC," Hopkins wrote.

That preserves three distinct routes to a bid ceiling, each with different operational costs.

Portfolio bid strategies apply a single strategy across multiple campaigns that share a goal, allowing the system to balance spend between over- and under-performing campaigns inside the group. Microsoft extended Max Conversion Value to portfolio strategies in September 2024, and portfolio structures were the exception left untouched by the August 2025 consolidation as well. For the second time in roughly thirteen months, the portfolio container is the place where a control removed from standard campaigns continues to exist.

Enhanced CPC occupies a different position. Microsoft moved native image and feed campaigns off manual CPC and onto eCPC in 2024, with manual CPC unavailable for new campaigns of those types from April 30, 2024 and existing campaigns upgraded between May 13 and May 17 that year. Under eCPC the advertiser sets a base bid that the system adjusts upward or downward per auction according to estimated conversion likelihood. The base bid survives; the certainty about what any individual click costs does not.

Target impression share is a visibility strategy rather than a conversion strategy, and its bid ceiling exists to stop the pursuit of a placement target from running costs to arbitrary levels.

Hopkins also restated a separate piece of platform behaviour in the same post. Microsoft Advertising, she wrote, "continues to allow campaigns to over achieve on TCPA/TROAS regardless of budget limited status." She pointed advertisers toward conversion value rules, describing them as "more effective ways of communicating with the bidding algorithm."

That sentence lands with unusual timing. Three days ago, on August 17, 2026, Google began rolling out a change that pushes over-performing Target CPA and Target ROAS campaigns back toward their stated figures in budget-limited Search, Shopping, Performance Max, Demand Gen and Travel campaigns. Hopkins is describing the opposite posture on the same mechanic, in the same week, without naming the competitor.

Bidner, who runs a freelance Google Ads consultancy, framed the removal as a loss of something Microsoft had done better than its larger rival. "i have always loved how smart bidding in microsoft had the max cpc cap natively in it and it didnt need a portfolio strategy," he wrote. "this sucks they are taking that away."

His post opened with the line "just when i thought the cruelty was over," a reference that carries context. Bidner was the practitioner whose July 15, 2026 post gathered 71 reactions and 27 comments after he described Google's August 17 bidding target change as the most frustrating Google Ads update he had encountered. Google subsequently rejected the claim that the change reached campaigns not limited by budget.

Engagement on both of today's posts was modest at the time of capture. Bidner's carried eight reactions and four comments; Hopkins' carried five reactions and one comment, with her own follow-up comment linking to documentation. Those counts are snapshots taken within roughly fifty minutes of publication and are not a measure of eventual reach.

In a comment on her own post, Hopkins directed advertisers to Microsoft's help article on Search optimization experiments. The choice is deliberate: an experiment is the mechanism the platform offers for measuring what a bidding change does before it is applied at full budget.

According to that documentation, an experiment creates a duplicate of a Search campaign which receives a split of the original campaign's budget and ad traffic. The eligibility perimeter is narrow. Only Search campaigns qualify, and experiments cannot be created for campaigns with Dynamic Search ads enabled in the campaign settings.

The configuration steps carry several locks. The default start date is the day after creation, which the documentation frames as time to make the changes being tested. An end date is optional. The experiment split determines what percentage of the original campaign's budget and traffic goes to the test, and Microsoft recommends 50/50 so that the experiment receives enough traffic for a fair comparison. That split cannot be altered while the experiment runs.

An advanced setting governs how traffic is assigned. Under the search-based option, customers are randomly shown either experiment ads or original campaign ads each time they search, which means an individual can see both if they search more than once. Under the cookie-based option, a cookie fixes each customer to one source for all subsequent searches. This setting is also locked once the experiment is running.

Budget sits outside advertiser control at the experiment level entirely. According to the documentation, changing an experiment's budget requires changing the original campaign's budget, after which the new figure is divided according to the split setting. Any other change made to the original campaign while an experiment runs does not propagate to the experiment, and Microsoft advises against making such changes at all so that the comparison holds.

Results appear as a metric comparison table with colour coding: green where the experiment outperforms the original campaign on that metric, red where it underperforms, and grey where no statistically significant difference exists between the two. Statistical significance is displayed beneath each metric value.

Two exit routes exist. Applying an experiment to the original campaign transfers all experiment settings into it, ends the experiment, and returns the original to the full budget and traffic it started with. Applying it to a new campaign pauses the original and creates a fresh campaign carrying the experiment's settings and the original's budget. Experiments can also be stopped early through End experiment now, and removed entirely through Edit and then Delete experiment.

Eight statuses populate the Experiments table: Active, Creating experiment, Experiment creation failed, Scheduled, Completed, Applying experiment, Experiment applied, and Applying experiment failed.

The help documentation Hopkins linked does not mention Max CPC. It predates the notice in substance, describing experiment mechanics in general terms, and it carries a 2026 Microsoft copyright footer without a visible revision date tied to this change.

That leaves an interaction unaddressed in either source. One of the two ways to conclude an experiment is to apply it to a new campaign, which the documentation states will be created with the current settings of the experiment. Whether a campaign created through that path counts as a new non-portfolio campaign for the purposes of the October 1 restriction is not stated anywhere in the material published so far. Advertisers running a Max CPC experiment in the final weeks of September would be the first to encounter the question.

A second gap concerns tooling. Microsoft Advertising makes new API features exclusive to the REST interface from October 1, 2026, with full SOAP deprecation following on January 31, 2027. The bidding restriction and the API boundary share a date. Neither notice references the other, and no statement has been published on how the Max CPC field behaves for campaign creation through the API, Microsoft Advertising Editor, or bulk upload after that date.

Manual bid ceilings have been receding across the major search and app platforms for two years. Google sunset Enhanced CPC for search and display by March 2025. Apple replaced the CPA cap in App Store search campaigns with a target-CPA system in February 2026. Microsoft removed standalone Target CPA and Target ROAS in August 2025.

The pattern is not uniform. Google reversed part of its own simplification when it restored Target CPA and Target ROAS as standalone strategy labels in June 2026, though the underlying logic was unchanged. What has moved consistently in one direction is the availability of hard ceilings on what an auction can charge, as distinct from targets that guide an algorithm toward an average.

The distinction matters mechanically. A target is an instruction about a mean outcome. A cap is a constraint on an individual transaction. Removing the cap while retaining the target changes which party absorbs the variance around that mean.

Microsoft has been shipping platform changes at an accelerated cadence through 2026. AI Max reached all Microsoft Advertising accounts globally yesterday, bundling search term matching, text customisation and URL expansion under a single campaign toggle. Predictive Matching was folded into that suite in late July. Bulk editing and appeals for disapproved assets went live on August 6, and the Ad Preview Hub arrived inside Performance Max on July 28. A separate change to UTM auto-tagging takes effect on September 2.

Microsoft reported search advertising revenue excluding traffic acquisition costs up 10 percent in its fiscal fourth quarter, or 9 percent in constant currency, for the three months ended June 30, 2026. That was the second deceleration in three quarters against a sequence that had run at 21 percent through fiscal 2025. Full-year search advertising revenue reached 15.176 billion dollars, against 13.878 billion dollars in fiscal 2025. Chief financial officer Amy Hood guided to mid-single-digit growth for the first quarter of fiscal 2027.

October 1, 2026 is the first day of Microsoft's fiscal second quarter. The Max CPC restriction lands at the start of the period that follows the one Hood has already flagged as soft, and it lands ahead of the fourth-quarter retail season when auction pressure is at its annual peak.

Nothing in either source document connects the bidding change to revenue. The proximity is a matter of calendar, not of stated intent, and Microsoft has published no rationale for the removal beyond the notice itself.

The practical exposure sits with advertisers who use a Max CPC as a guardrail rather than as a primary lever. Search campaigns built on Maximize Conversions or Maximize Conversion Value with a target attached have, on Microsoft, been able to carry a native ceiling without the account restructuring a portfolio strategy requires. From October 1 that combination is unavailable at creation.

Portfolio strategies are the obvious substitute, but they are not a neutral swap. A portfolio governs multiple campaigns as a unit, which means budget can shift between campaigns inside the group according to the platform's assessment rather than the buyer's allocation. For agencies running client campaigns with per-campaign spend commitments, that structural difference has reporting and contractual consequences that a single bid field does not.

Enhanced CPC keeps a base bid but permits the system to exceed it per auction. Target impression share keeps a ceiling but reorients the campaign around placement rather than conversions.

Six weeks separate today's notice from the effective date. Microsoft's own recommended test window under the experiments framework, at a 50/50 split with enough traffic for statistical significance, sits inside that gap but not comfortably. Advertisers evaluating whether a portfolio restructure changes cost-per-click outcomes have one testing cycle available before the option to build a new campaign the old way closes.

• April 30, 2024 - Manual CPC becomes unavailable for new Microsoft native image and feed campaigns, with existing campaigns upgraded to enhanced CPC between May 13 and May 17
• September 2024 - Microsoft extends Max Conversion Value to portfolio bid strategies
• March 2025 - Google completes the sunset of Enhanced CPC for search and display
• August 4, 2025 - Microsoft removes Target CPA and Target ROAS as standalone strategies for new campaigns, leaving portfolio strategies untouched
• February 26, 2026 - Apple replaces the CPA cap with Maximize Conversions across App Store search campaigns
• April 1, 2026 - Microsoft sets the SOAP API retirement schedule, with new features REST-only from October 1, 2026
• June 15, 2026 - Google discloses the bidding target change scheduled for August 17
• June 2026 - Google restores Target CPA and Target ROAS as standalone strategy labels
• July 15, 2026 - Joey Bidner's criticism of the Google bidding change draws 71 reactions and 27 comments
• July 29, 2026 - Microsoft reports fiscal fourth-quarter search advertising growth of 10 percent excluding traffic acquisition costs
• August 17, 2026 - Google begins rolling out target-based bidding changes for budget-limited campaigns across five formats
• August 19, 2026 - AI Max becomes available across all Microsoft Advertising accounts globally
• August 20, 2026 - Microsoft notification emails and a Navah Hopkins LinkedIn post confirm Max CPC removal from new non-portfolio campaigns
• October 1, 2026 - Max CPC becomes unavailable when creating new non-portfolio campaigns; new Microsoft Advertising API features become REST-exclusive on the same date
• January 31, 2027 - Full deprecation of the Microsoft Advertising SOAP API

• Microsoft consolidates bidding strategies - The August 4, 2025 removal of standalone Target CPA and Target ROAS, including the automatic conversion mechanics absent from the current notice.
• Microsoft Advertising transitions away from manual CPC to enhanced CPC - The 2024 native ads precedent for withdrawing a manual bid control from new campaigns first.
• Microsoft Advertising expands portfolio bid strategies with Max Conversion Value - How portfolio structures pool optimisation across campaigns sharing a goal.
• Microsoft Advertising launches Experiments globally - The 2021 global rollout of the A/B testing framework Hopkins pointed advertisers toward.
• Microsoft Advertising kills SOAP API: what the October 2026 deadline means - The API boundary that shares an effective date with the bidding restriction.
• Microsoft Advertising gains AI Max across all accounts globally - Yesterday's global rollout of the search expansion suite and its three campaign settings.
• Microsoft kills Predictive Matching, shifts Search ads to AI Max - The feature retirement that folded query expansion into the AI Max toggle.
• Google today forces overperforming CPAs up across 5 campaign types - The August 17 change that runs opposite to the over-achievement behaviour Hopkins restated.
• Google Ads bidding overhaul forces CPAs to double, sparking backlash - The July practitioner criticism that included Bidner's earlier post.
• Google denies broader Smart Bidding change as August 17 nears - Google's rejection of the claim that unconstrained campaigns were affected.
• Google to sunset Enhanced CPC for search and display ads by March 2025 - The competing platform's earlier withdrawal of a semi-manual bidding option.
• Apple rolls out Maximize Conversions to all App Store advertisers - The App Store equivalent, replacing a cap mechanism with a target system.
• Microsoft search ad growth drops to 10% as Azure tops $100 billion - Fiscal fourth-quarter results and the mid-single-digit guidance for the quarter preceding the change.
• Microsoft Advertising's UTM fix will finally separate Bing campaign types - The September 2 auto-tagging change arriving four weeks before the bidding restriction.

Who: Microsoft Advertising, with the change communicated through advertiser notification emails and a LinkedIn post by Navah Hopkins, Microsoft Ads Liaison. The email was circulated publicly by Joey Bidner, a freelance Google Ads manager and coach. The restriction affects advertisers, agencies and in-house teams that create new Search campaigns on the platform without using a portfolio structure.

What: Max CPC will no longer be available when creating new non-portfolio campaigns. Target impression share, enhanced CPC and portfolio bid strategies retain the ability to add a Max CPC. The notice does not address campaigns already running with a Max CPC configured, does not describe an automatic migration path, and does not state how the restriction interacts with experiments applied to new campaigns or with campaign creation through the API and bulk tools.

When: The notification and the liaison post surfaced on August 20, 2026. The change takes effect on October 1, 2026, a Thursday, which is also the date new Microsoft Advertising API features become exclusive to the REST interface and the first day of Microsoft's fiscal second quarter.

Where: Across Microsoft Advertising campaign creation. The day-month-year date format in the notification indicates European or United Kingdom message localisation, and no geographic carve-outs were stated.

Why: No rationale for the removal appears in the notice or the liaison post. Hopkins used the same post to restate that Microsoft continues to allow campaigns to over-achieve on TCPA and TROAS regardless of budget-limited status, and pointed advertisers toward conversion value rules and Search optimization experiments. The change extends a multi-platform pattern in which hard bid ceilings are withdrawn from standard campaign creation while advertiser-set targets remain, shifting auction-level cost variance from the platform's constraint to the advertiser's tolerance.