Google changes Smart Bidding on 17 August: what you need to do now

A change is coming to Google Ads that's rippling through the entire advertising world these weeks, and it will cost some advertisers money if they do nothing. From 17 August 2026, Google will optimise target-CPA or target-ROAS campaigns that are limited by budget much more strictly towards that set goal.

Sounds technical and harmless. It isn't. For part of these campaigns it simply means: your cost per lead is going to rise towards the number you entered years ago and never touched again.

In this article we explain what's changing, why Google is doing this, how to see if it affects you, and which steps to take before 17 August.

What exactly is changing

The mechanics in short. When you use Smart Bidding (target CPA or target ROAS) you give Google a goal: "get me leads for a maximum of €45" or "get me at least 400% revenue per ad euro spent." Google then decides per auction how much to bid to hit that goal.

If your campaign is stuck at its daily budget — status "Limited by budget" — something has, until now, worked in your favour. Because demand exceeded budget, Google mostly picked the auctions most likely to convert cheaply. Result: campaigns that performed much better than their own goal. Target CPA set at €45, actual leads coming in at €31.

That €14 gap was effectively free margin. Google now says this was never the intention.

From 17 August, Google will consistently optimise those budget-limited campaigns towards the goal you entered. If your target is €45 and you're currently getting €31, your real CPA will move towards €45. You do get something in return: more volume and much more predictable behaviour when you raise or lower your budget.

Why Google is doing this

It sounds contradictory — why would Google make a campaign that outperforms its target less efficient? The logic is scalability.

Under the old behaviour, the effect of raising your budget was unpredictable. You'd double your budget, and instead of twice as many leads at the same price you'd get slightly more leads at a much higher price, because the system stepped out of its frugal auction selection. Advertisers were reluctant to scale up as a result.

After the update: the goal you enter is the goal you get — whether you spend €20 or €200 a day. That turns scaling up into a calculation instead of a gamble. The auction itself doesn't change; this is purely a bidding change.

Who's affected and who isn't

Affected:

• Campaigns with target CPA or target ROAS that have "Limited by budget" status
• Search, Shopping, Performance Max and Demand Gen campaigns (Demand Gen also includes target CPC)
• And within that group, especially: campaigns that structurally outperform their set goal

Not affected:

• Campaigns that aren't limited by budget — they were already following the goal
• Manual CPC and target impression share
• App campaigns, Video reach and Video views (these keep the old behaviour)
• Display and Hotel — these already work on the new model

For Performance Max and Demand Gen something extra can happen: because bidding shifts, the distribution of your traffic across channels can also change. A campaign that leant heavily on Shopping placements may shift more towards Display or YouTube. So don't just watch your CPA, also watch where your impressions come from.

How to check in ten minutes whether it affects you

1. Filter by status. Open your campaign overview and filter on "Limited by budget." Only those campaigns are relevant.
2. Put target next to reality. Add the target CPA/ROAS and actual CPA/ROAS columns for the last 30 to 60 days.
3. Look for the gap. If a campaign performs clearly better than its target (actual CPA much lower, or ROAS much higher than the target), that's a risk campaign.
4. Use the Bid Target Adjustment Tool. Google has had a tool in Google Ads since early July that identifies exactly these campaigns and suggests an adjusted target. Treat it as a starting point, not a final verdict.
5. Check your notifications. Affected accounts get in-interface notices. No notice doesn't automatically mean you're safe — do steps 1 to 3 yourself anyway.

Important: Google does not automatically adjust anything. Your budgets stay as they are and your targets are not lowered for you. Doing nothing is a choice with consequences.

What to do before 17 August

Option 1 — hold on to current performance. If a campaign performs at €31 while the target is set at €45, set the target to roughly €31. You keep your efficiency, with a slightly smaller volume than Google could have given you after the update.

Option 2 — deliberately buy volume. If you know a lead can cost you up to €45 and that's commercially healthy, leave the target as is and use the update to grow. Consider raising your budget too, since the campaign becomes more predictable to scale after 17 August.

Option 3 — somewhere in between. In practice this is usually what we choose: set the target a bit above current performance (say €35 with an actual CPA of €31), so you buy some extra volume without giving away your margin.

Things to do in every case:

• Record your baseline. Export CPA, ROAS, conversions, cost and channel distribution per campaign for the 30 days before 17 August. Without that baseline you can't prove what changed after the update.
• Change one thing at a time. Don't adjust targets, raise budgets and launch new creative all at once. Three weeks later you won't know what caused the difference.
• Know your real maximum. Work out your allowed CPA from your margin and your lead-to-customer conversion rate, not from a gut feeling. This update is the moment a wrong target number suddenly shows up in your costs.
• Check your conversion tracking. Optimising towards a goal only works if the conversion point you're measuring truly represents value. If every form click still counts as a conversion, Google will soon optimise neatly towards noise.
• Look beyond the first week. After a bidding change, Smart Bidding needs a learning period. Don't draw conclusions from three days of data.

What this says about the bigger picture

This update doesn't stand on its own. Since AI Max, Performance Max and Demand Gen, Google Ads has been moving towards one model: you supply goals, signals and creative, Google handles the execution. Keywords, placements and bids are increasingly fewer dials you turn yourself.

The consequence is that the quality of your input becomes decisive. Accurate conversion values, a target calculated from your margin, good feeds, strong landing pages and enough signal from your CRM about what a lead is really worth. In a world where the system literally delivers what you enter, a sloppily entered target number is no longer a detail — it's a direct loss.

And that's exactly why with Google Ads we always start with the economics behind the campaign rather than the settings.

In short

• From 17 August 2026, Google optimises budget-limited target-CPA and target-ROAS campaigns more strictly towards the set goal.
• Campaigns currently outperforming their goal will see their CPA rise or their ROAS fall towards that goal.
• Google does not automatically change your targets and budgets — you have to act.
• Check campaigns with "Limited by budget" status, compare target to actual performance, and adjust the target before 17 August.
• Record a baseline so you know exactly what the effect was after the update.

Want us to review your account before 17 August and set a target per campaign that's calculated from your margin? Get in touch.