A higher CPC since 17 August 2026 may have several causes. One is Google’s change to budget-limited Target CPA and Target ROAS campaigns, which, according to smec, stopped accumulating surplus. Others are seasonality, competition, changes in ads, audiences or settings. This seven-step diagnosis helps separate the causes, without concluding before you have comparable data.
Step 1: confirm CPC really rose
Before looking for causes, confirm the effect. Compare average CPC in the 4 weeks before 17 August with the 4 weeks after, per campaign, not just for the account. An account average can hide that one campaign rose a lot and others fell. Use the same period last year as a second reference, if you have data.
The CPC change should be read with cost per result: a higher CPC may be acceptable if conversion rate rises or ROAS holds. What matters for the business is cost per customer, not the price of each click.
Step 2: identify candidate campaigns
Candidate campaigns for the effect are those using Target CPA or Target ROAS (including those which, in the interface, came to be called “Target CPA” instead of “Maximize conversions with a Target CPA”, a label change from June 2026 with no behaviour change) and which are budget-limited. See the campaign status and impression share lost to budget.
If the campaign isn’t budget-limited, the 17 August change isn’t the likely cause. If it uses manual CPC, video or app, neither, according to the sources consulted.
CPC diagnosis in seven steps
- Confirm the rise, per campaign
- Identify budget-limited Target CPA or ROAS campaigns
- Rule out seasonality and competition
- Review the change history
- Wait the right cycle and decide with a record
Step 3: rule out seasonality and competition
October and November are months of higher demand and competition in many sectors, with Black Friday on 27 November. Compare with the same period last year. Look at auction data (impression share, top share, competitors) to see whether there are new competitors or more pressure.
If CPC rose in campaigns that aren’t budget-limited at the same time, the cause is probably market, not the bidding change. This distinction between limited and non-limited campaigns is the best clue you have.
Step 4: review the change history
In the change history, see what changed in the campaigns concerned: budgets, targets, ads, keywords, audiences, negative lists, bidding strategies. A change made by you or the team at the same time may explain the rise.
A good practice is to keep an event log outside the platform, with dates and reasons. When a number changes, the log shows what else changed. Without it, it’s easy to attribute to Google what was an internal decision.
A higher CPC is only bad if cost per customer also rises.
Step 5: see what happened to volume
If CPC rose and conversion volume held or rose, cost per result may even have improved. If volume fell and cost per result rose, there’s a real problem. If ROAS moved closer to the target and volume fell a bit, it’s consistent with the new logic: the campaign stopped “lowering the bid to save budget”.
Record the four numbers: CPC, conversion rate, conversion volume and cost per result, before and after. With them, the decision stops being based on feelings.
Step 6: wait for the right cycle
Google recommends waiting one to two conversion cycles before assessing performance after a target change. If your decision cycle is long (B2B, high ticket), this may mean several weeks. Avoid touching budgets and targets reactively with every oscillation.
If pressure is high (for example Black Friday), reduce risk with limits: a spend ceiling, pause rules for campaigns outside the cost limit and frequent reviews, without drastic changes.
Step 7: decide and document
With the data in hand, choose: keep (it’s on target and cost per customer is acceptable), adjust the target, raise the budget, restructure or stop. Record the decision, the reason and the review date. Share with whoever runs or approves the account.
If, after all this, the cause isn’t clear, you can ask Google for support or an independent professional. A second opinion from someone who doesn’t run the account helps see what goes unnoticed by those inside it.
An illustrative reading example
A Portuguese online shop sees the average CPC of a Shopping campaign go from €0.40 to €0.52 after 17 August. The campaign uses Target ROAS and is budget-limited. Conversion rate holds and ROAS approaches the target. The brand search campaign, with no budget limit, kept its CPC. The probable reading: the rise is linked to the new bidding logic in the limited campaign, and ROAS “normalised”. The decision: raise the budget a little and review the target.
The example is hypothetical, but shows the reasoning: separate campaigns, compare controls and decide with numbers.
Frequently asked questions
How do I know if my campaign is budget-limited?
The platform shows the “limited by budget” status and shows impression share lost to budget. Confirm in your account.
Should I raise the budget?
Only if cost per result is acceptable and margin allows. Raise in steps and measure.
Is a CPC rise always bad?
No. Assess with cost per result and ROAS. A higher CPC with more conversions at the same cost may be neutral or good.