Google Ads Portfolio Bidding Strategies: When and How to Use Them
Google Ads offers a wide range of bidding strategies, but one of the most underused advanced features is the portfolio bidding strategy. While many advertisers manage bidding at campaign level, portfolio bidding allows you to control bidding across multiple campaigns from a single shared strategy.
For advertisers managing larger accounts or struggling with inconsistent CPCs, portfolio bidding strategies can provide greater flexibility, improved efficiency, and additional controls that are not available with standard campaign-level bidding.
In this guide, we’ll explain:
- What a portfolio bidding strategy is
- How it differs from standard bidding strategies
- The biggest advantages of using portfolio bidding
- How to use CPC limits with smart bidding
- When portfolio bidding makes sense
- How to set one up in Google Ads
What Is a Portfolio Bidding Strategy in Google Ads?
A portfolio bidding strategy allows you to apply a single Google Ads smart bidding strategy across multiple campaigns at account level rather than configuring bidding individually for each campaign.
Instead of every campaign having:
- Its own bid strategy
- Its own target CPA or ROAS
- Its own budget management
…you can centralise bidding through a shared strategy inside the Google Ads Shared Library.
Portfolio strategies support Google’s smart bidding options, including:
- Target CPA
- Target ROAS
- Maximise Conversions
- Maximise Conversion Value
- Target Impression Share
- Maximise Clicks
This means multiple campaigns can effectively work together towards the same goal.
Why Use Portfolio Bidding Strategies?
Portfolio bidding strategies offer several advantages over standard campaign-level bidding.
1. Shared Learning Across Campaigns
One of the biggest benefits is that campaigns can share data and learning signals.
For example, imagine you have several campaigns all aiming for:
- A £30 target CPA
- Similar audiences
- Similar products or services
With separate campaign strategies, each campaign learns independently.
With portfolio bidding:
- Google pools signals together
- Campaigns work collectively
- The algorithm can optimise more efficiently across the account
This is especially useful when individual campaigns have lower conversion volume.
2. Better Budget Distribution
Portfolio strategies can also help distribute spend more efficiently between campaigns.
Some days:
- One campaign may experience lower search demand
- Another campaign may see increased traffic opportunities
Instead of rigid campaign budgets limiting performance, Google can allocate spend more dynamically across campaigns using the shared strategy.
This creates a more flexible account structure and can help reduce wasted budget.
3. Additional Bid Controls Not Available at Campaign Level
This is arguably the most powerful feature of portfolio bidding strategies.
With a portfolio strategy, you can apply:
- Maximum CPC bid limits
- Minimum CPC bid limits
…alongside smart bidding strategies like Target CPA.
This is something you cannot normally do at standard campaign level.
Using Max CPC Limits with Smart Bidding
Normally, when running a Target CPA campaign, Google has complete control over CPCs.
That means the platform may sometimes increase bids aggressively in order to chase conversions.
In some accounts, this works well.
In others, CPCs can spiral out of control.
Portfolio strategies allow you to introduce a “guard rail” by setting a maximum CPC limit.
Why This Matters
Some advertisers experience situations where Google dramatically increases CPCs during periods of low demand.
For example:
- Average CPC on a normal day = £4–£5
- Average CPC on quieter days = £20–£25
When this happens:
- Budget disappears rapidly
- Fewer clicks are generated
- Cost efficiency collapses
Using a portfolio strategy with a maximum CPC limit prevents Google from bidding excessively high while still allowing smart bidding automation to function.
Real-World Example
Consider a B2B advertiser using Target CPA bidding.
On most days:
- CPCs average around £4–£5
However, during low-demand periods:
- Google increases bids aggressively
- CPCs jump to £20+
- Budget gets exhausted quickly
To solve this, the advertiser applies:
- A Target CPA portfolio strategy
- A maximum CPC limit of £9
This gives Google enough room to optimise while preventing extreme CPC inflation.
The result:
- More stable spend
- Better budget control
- Improved efficiency
The Danger of Setting CPC Limits Too Low
While maximum CPC limits are useful, they must be implemented carefully.
If the limit is too restrictive, the campaign may struggle to spend or scale.
Google may even show a:
“Bid strategy limited” status
This means the CPC restriction is preventing the strategy from achieving its target.
Common Mistake
Many advertisers mistakenly set their max CPC equal to their average CPC.
For example:
- Average CPC = £2
- Max CPC limit = £2
This is usually far too restrictive.
Remember:
- Average CPC is only an average
- Some clicks naturally cost more
- Smart bidding needs flexibility
A better approach is to treat the limit as a safeguard, not a manual CPC target.
Best Practice for Max CPC Limits
When setting a maximum CPC limit:
Good Approach
- Average CPC = £4–£5
- Max CPC limit = £8–£10
This gives Google room to optimise while protecting against extreme bids.
Bad Approach
- Average CPC = £4–£5
- Max CPC limit = £4–£5
This often over-constrains the algorithm.
When Should You Use Portfolio Bidding?
Portfolio bidding strategies work best in situations where:
Multiple Campaigns Share the Same Goal
For example:
- Same target CPA
- Same ROAS target
- Similar conversion objectives
You Want Greater CPC Control
Particularly useful when:
- CPC volatility is high
- Google overspends during low demand periods
- Budget pacing becomes inconsistent
Your Campaigns Have Lower Conversion Volume
Shared learning across campaigns can help smart bidding stabilise faster.
You Manage Larger Accounts
Portfolio strategies simplify account management by reducing duplicated settings across campaigns.
How to Set Up a Portfolio Bidding Strategy in Google Ads
Setting up a portfolio strategy is relatively straightforward.
Step 1: Open Shared Library
In Google Ads:
- Go to Tools & Settings
- Under Shared Library
- Click Bid Strategies
Step 2: Create a New Portfolio Strategy
Click the blue + button.
You’ll then choose your bidding type, such as:
- Target CPA
- Target ROAS
- Maximise Conversions
For this example, use Target CPA.
Step 3: Name the Strategy
Use a clear naming convention.
Example:
Target CPA £30 – Max CPC £5
This makes future management much easier.
Step 4: Select Campaigns
Choose all campaigns that should use this strategy.
These campaigns should ideally:
- Share similar goals
- Have similar economics
- Require similar bidding behaviour
Step 5: Set Your Target CPA
Enter your desired CPA target.
Example:
£30
Step 6: Configure Advanced Options
Open the Advanced Options section.
Here you can set:
- Minimum CPC bid limit
- Maximum CPC bid limit
Most advertisers focus on the maximum CPC setting.
Example:
Max CPC = £5
Step 7: Save the Strategy
Once saved:
- The portfolio strategy overrides campaign-level bidding
- Campaigns begin sharing the strategy
- CPC constraints become active
Final Thoughts
Portfolio bidding strategies are one of the most powerful yet overlooked features in Google Ads.
They offer:
- Shared learning across campaigns
- More efficient budget allocation
- Centralised bidding control
- Protection against excessive CPC inflation
For advertisers struggling with volatile CPCs or managing multiple campaigns with identical goals, portfolio bidding can significantly improve account stability and efficiency.
The key is implementation.
If you set CPC limits too aggressively, you may restrict performance. But when configured correctly, portfolio strategies provide an excellent balance between automation and control.
For many advertisers, they represent the best of both worlds.
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