In digital advertising, bid strategies have long been one of the automated features advertisers trust most: set the target and leave the rest to the system. But Google has recently officially announced that from 17 August 2026, Smart Bidding will undergo a major change: campaigns limited by budget will no longer “quietly save you money”, but will spend fully in line with the target you have set.
What does this mean? The days of setting a target CPA of NT$300 and actually spending only NT$180 are coming to an end. If you leave things as they are, the same budget may deliver noticeably fewer conversions. This is also a reminder for advertisers to keep a reasonable eye on their accounts.
So what exactly has changed, which campaigns are affected, and what should advertisers prepare before 17 August? This article sets it all out.
What does the 17 August Google Ads bidding change do?
In one sentence: from 17 August 2026, for campaigns that are “limited by budget” and use target CPA or target ROAS, the system will optimise more consistently towards the target you set and will no longer automatically bid conservatively. For campaigns whose actual performance used to beat the target, costs will rise back to the target level.
The timeline is as follows:
From 6 July 2026: affected accounts start receiving notifications, and the Bid Target Adjustment Tool becomes available within the account.
From 17 August 2026: the change takes effect gradually over several weeks.
17 to 31 August 2026: Google warns that forecasting features such as Performance Planner may be inaccurate, so interpret them cautiously.
| Aspect | Before 17 August | After 17 August |
|---|---|---|
| Role of the target | A reference ceiling; the system often bids conservatively | A value to execute; the system optimises to the target |
| Actual performance | Often better than the target (overachieving) | Close to the target |
| When budgets are adjusted | Performance tends to fluctuate and is hard to predict | Performance stays steadily close to the target |
| Total spend | Controlled by the daily budget cap | Unchanged; budget caps work as before |
Note in particular that Google has stated clearly that it will not automatically adjust targets or budgets for advertisers. Whether and how to respond is entirely up to the advertiser.
Why will the system spend up to the target?
The key point is that the system isn’t making cheap conversions more expensive. It is using the target as a “maximum willingness to pay” and using it in full. It still competes for cheap auctions, but it will now also bid in auctions it used to pass on as too expensive. The newly added conversions cost more per unit, pulling the average cost towards the target.
Ad delivery is essentially a series of auctions, and every impression has a different price. Think of an auction house: you ask a friend to bid for you and tell them “no more than 300 per item”. Some items can be won for 180, while others need 280 to win. Previously they only bid on the cheap ones. After 17 August they will use the full authority you gave them, bidding for the 180 items as before and competing for the 280 ones too.
As a result, three things happen at once:
- Cheap conversions are still bought: high-intent, low-cost traffic won’t be given up. This part doesn’t change.
- More expensive conversions are added: more competitive time slots and keywords, and lower-intent audiences, that previous bids couldn’t win are now within reach. Roughly speaking, the reach widens from “high-intent users” to “moderate-intent users”.
- Average cost rises: with old and new traffic mixed together, the average CPA moves from the actual figure towards the target.
For cross-placement campaigns such as Performance Max (PMax) and Demand Gen, budget allocation between placements may also shift. This change means the “target” field can no longer be left untouched.
Which campaigns are affected?
A campaign is only affected when both conditions apply: its status shows “Limited by budget”, and it uses target CPA, target ROAS, or Demand Gen’s target CPC. Campaigns that meet only one of the two conditions behave as before.
First, three key terms:
- Target CPA: tells the system “how much I’m willing to spend for each conversion (order or lead)”.
- Target ROAS: tells the system “how much revenue I need back for every 1 dollar of ad spend”.
- Limited by budget: the system wants to spend more than the daily budget. This label appears in the “Status” column of the campaign list.
| Covered by the change | Not affected |
|---|---|
| Search campaigns Shopping campaigns Performance Max (PMax) Demand Gen (including target CPC) Travel campaigns Portfolio bid strategies and shared budgets (adjusted at portfolio level) |
App campaigns Video reach and video view (VVC) campaigns Manual CPC and target impression share Target-based campaigns not limited by budget (Display and hotel campaigns already use the new behaviour) |
The platforms covered include Google Ads, Search Ads 360, Display & Video 360, Google Ads Editor and the API, so all the main management interfaces are included.
Worked example: target CPA of NT$300, what’s the difference before and after 17 August?
The numbers make it clearest. Take a lead generation campaign with a target CPA of NT$300, a daily budget of NT$1,000, status showing “Limited by budget”, and a recent actual CPA of NT$180.
| Scenario | Actual CPA | Leads per day (budget NT$1,000) |
|---|---|---|
| Before 17 August | About NT$180 | About 5 |
| After 17 August (no change) | Moves towards the NT$300 ceiling set | About 3 |
| Target changed to 180 before 17 August | Stays at about NT$180 | Stays at about 5 |
The same amount is spent, but leads fall from 5 to 3. And this isn’t a system fault. The system is faithfully executing the number written in the account. This is also the logic of Google’s own example: a campaign with a target of US$10 that is actually running at US$5 will move towards US$10 if it isn’t adjusted.
How should advertisers respond? 3 steps to prepare
The response is simple: before 17 August, find campaigns where there’s a big gap between the target and actual performance, and change the target to a number you genuinely accept. There are three specific steps.
Step 1: review affected campaigns. Open the Campaigns list in Google Ads and filter for campaigns with “Limited by budget” in the Status column and target CPA or target ROAS in the Bid strategy column. Note down the “set target” and the “actual performance over the last 30 days” and compare them. Accounts that have received Google’s notification can also review directly with the Bid Target Adjustment Tool in the account.
Step 2: choose one of four options.
- Keep the current target: if the target already reflects your business goals, there’s no need to change it. But campaigns that used to overachieve will see performance fall back to the target level.
- Align with recent performance: if you want to keep your current good cost level, click “Apply” in the adjustment tool, as in the example above, changing 300 to 180.
- Set a new custom target: if 250 is acceptable for the business, set 250, and spend will then track that number. The principle is that the target should be a consciously chosen number.
- Switch to Maximise conversions: switching to a bid strategy without a target can protect volume, but cost will fluctuate with budget. This suits campaigns where volume is the priority.
Step 3: after the change takes effect, observe for one to two conversion cycles. The change rolls out gradually over several weeks. Watch CPA/ROAS trends and budget pacing, and fine-tune only if something looks wrong. Don’t make big changes all at once, which would restart the learning period. Treat forecasting tool figures for 17 to 31 August as reference only.
Google also offers an incentive: after the change, the system will optimise steadily towards the target, so adding budget to scale up will no longer make performance swing up and down. For brands that want to increase reach, this is actually good news. You can use this change as an opportunity to review your account and recalibrate the targets for all campaigns while you’re at it.
Conclusion: the target is now a number that will be used in full
What this change really alters is the meaning of the “target” field. In the past it was more like a reference value, and the system’s actual spend was often below it. After 17 August, the system will treat it as an allowance that can be used in full. For advertisers who manage their accounts regularly, the impact will be small. But if a target hasn’t been reviewed for a long time, the actual average cost may gradually move towards that old number after 17 August.
There’s no need to rush into action right now. As long as you check and adjust the targets of budget-limited campaigns before 17 August, you’ll be fine. Once they’re set, the system will execute according to the amounts you’ve set. It won’t add extra spend, and it won’t change your settings on its own.
In the first few weeks after the change, reports will fluctuate more than usual, and Google has also warned that performance forecasts between 17 and 31 August may not be very accurate. During this period, more important than rushing to change settings is reading the data clearly: which fluctuations are normal during the system’s transition, and which are signs that a target is set wrongly. Interpret clearly first, then adjust. To read the data from this period more clearly, see the data articles in our knowledge base.
Frequently asked questions
I’m not a professional media buyer. What’s the minimum I need to do?
Find campaigns that have both the “Limited by budget” label and target CPA/ROAS, and compare the target with actual performance over the last 30 days. Where the gap is large, use the adjustment tool in your account before 17 August to change the target to the actual figure, and you’ll keep your current cost level.
Will my campaigns be affected?
Only campaigns that are “Limited by budget” and use target CPA, target ROAS or Demand Gen target CPC are affected. App, video reach and video view campaigns keep the old behaviour.
Will total spend increase?
No. Google has stated clearly that daily and monthly budget caps work as before. What changes is the mix of traffic the same budget buys: average cost rises, and the number of conversions may fall.
What should the target be?
Use actual performance over the last 30 days as a baseline, set the CPA you’re genuinely willing to pay or the ROAS you genuinely need, and review it regularly when campaign periods and strategies change.
Does this apply to PMax and Demand Gen too?
Yes, and channel budget allocation in cross-placement campaigns may also change. Display and hotel campaigns already use the new behaviour, and App and video campaigns are not covered.
References
・Google Ads Help | Changes to target based bid strategies
・Google Ads Help FAQ | FAQ about changes to Target-based bid strategies
・PPC Land | Google Ads forces some CPAs to double starting August 17
・Search Engine Roundtable | Google Ads Changes With Bidding For Campaigns Limited By Budget
