Why Advanced Consent Mode Can Improve Performance Max Results

Most businesses treat cookie consent as a legal requirement. It isn’t. It’s marketing infrastructure.

If you’re running Google Performance Max campaigns and you haven’t reviewed how consent is implemented on your site, there’s a good chance your campaigns are learning from incomplete data. And that directly affects cost per lead.

The Problem Most Businesses Don’t See

Today, 30–50% of visitors will decline marketing cookies. In a traditional Basic consent setup, that means:

• Google Ads tags don’t fire
• No remarketing signal
• No conversion signal
• No behavioural data

From Google’s perspective, those users effectively disappear. Performance Max relies heavily on conversion data and behavioural signals to optimise bidding. Remove a large percentage of those signals and you reduce the quality of the data feeding the AI.
The result?

• Slower learning
• More volatility
• Higher cost per lead
• Smaller remarketing audiences

Most businesses never connect the dots between their cookie banner and their ad performance.

What Is Advanced Consent Mode?

Advanced Consent Mode is Google’s way of handling consent in a more intelligent way. The key difference is this:

• Tags still load on the page.
• If consent is denied, marketing cookies are not set.
• Instead, Google receives anonymous, cookieless signals.
• Google uses modelling to estimate conversions from declined users.

This does not bypass consent. It respects the user’s choice. But instead of losing all signal, it allows Google to maintain modelling strength. That distinction matters.

Basic vs Advanced: The Real Difference

Here’s the practical comparison:

With Basic mode, if someone declines cookies, Google has nothing to work with. With Advanced mode, Google can still use aggregated signals to inform bidding and optimisation. For Performance Max, that’s significant.

Why This Matters Specifically for Performance Max

Performance Max is not a manual campaign type. It is AI-driven. It relies on:

• Conversion data
• Audience behaviour
• Cross-device signals
• Intent modelling
• Historical performance

If 30–40% of your traffic disappears from measurement, the system has less information to learn from. That can lead to:

• Longer “learning” periods
• Sudden shifts in performance
• Inconsistent cost per lead
• Reduced audience expansion

Advanced Consent Mode doesn’t magically improve performance. What it does is protect signal quality when users decline cookies. That stability is often the difference between steady lead flow and fluctuating results.

Common Implementation Mistakes - check yours!

We’ve seen several recurring issues when reviewing consent setups:

• Mixing Google Tag Manager and hard-coded tracking scripts
• Consent defaults firing too late in the page load sequence
• Cookie plugins blocking scripts entirely
• Multiple systems trying to control consent
• Mixing "default" and "update" in the wrong places
• "Consent mode installation out of order" warnings ignored

The order matters. Consent defaults must be set before Google tags read consent state. If the sequencing is wrong, even a technically “installed” setup can behave incorrectly. This is where many businesses unintentionally downgrade themselves to Basic mode without realising it.

Where TCF v2.3 Fits Into This

The Transparency and Consent Framework (TCF) v2.3, developed by IAB Europe, is designed to standardise how consent signals are communicated across advertising vendors. For businesses targeting EU traffic or using programmatic advertising, TCF compliance becomes more important. In the UK, it isn’t strictly mandatory in the same way, but it still influences how consent signals are passed to ad platforms.

The important point is this:
TCF deals with how consent choices are structured and shared. Advanced Consent Mode deals with how Google models performance when consent is denied. They are related, but not the same. You can have a TCF-compliant banner and still run Basic mode. And you can implement Advanced Consent Mode without using a full TCF vendor framework. For most UK-based B2B businesses running Google Ads, the priority is ensuring Consent Mode is installed correctly and sequenced properly.

What a Proper Advanced Setup Looks Like

At a high level:

• Google Tag Manager loads on every page.
• Consent defaults are set immediately on page load.
• No marketing cookies are set until consent is granted.
• Google tags still load in a consent-aware state.
• User actions update consent cleanly.
• There are no duplicate tracking scripts.

It sounds simple, but the sequencing is critical. When implemented properly, you avoid:

• Out-of-order consent warnings
• Broken remarketing lists
• Incomplete conversion tracking

And more importantly, you protect the data feeding your campaigns.

Does This Matter for Smaller Accounts?

If you are spending a few hundred pounds a month on ads and generating minimal conversions, the impact may be modest. If you are:

• Running Performance Max
• Spending £1,000+ per month
• Relying on remarketing
• Generating regular B2B leads

Then signal quality becomes part of your marketing infrastructure. Advanced Consent Mode becomes worthwhile.

Consent Is Now Part of Performance

Consent is no longer just a compliance checkbox. It directly influences:

• How much data Google sees
• How well AI bidding performs
• How stable your campaigns are
• How large your remarketing pools become

If your Performance Max campaigns feel inconsistent, it’s worth asking:

• Is consent default set before tags load?
• Are scripts being blocked unnecessarily?
• Are multiple systems fighting each other?
• Are warnings being ignored in Tag Assistant?

Because in 2026, signal quality is competitive advantage. And consent architecture is part of that signal.

FAQs

Does Advanced Consent Mode track users without permission?
No. If a user declines marketing cookies, no advertising cookies are set. Advanced Consent Mode simply allows Google to receive anonymous, aggregated signals so it can model performance more accurately. it respects the user’s choice. It does not override it.

Is Advanced Consent Mode required by law?
No. Consent Mode itself is not a legal requirement. It is a technical framework provided by Google. What is required is compliance with GDPR, UK GDPR and PECR, which means obtaining valid consent before setting non-essential cookies. Advanced Consent Mode helps maintain advertising performance while respecting that legal requirement.

Do I need TCF v2.3 if I’m only targeting the UK?
Not necessarily. The Transparency and Consent Framework (TCF) v2.3, developed by IAB Europe, is more relevant if you are:
• Targeting EU audiences
• Using programmatic advertising networks
• Working with multiple advertising vendors
For many UK-based B2B businesses primarily using Google Ads, ensuring Consent Mode is implemented correctly is usually the priority.

Will Advanced Consent Mode improve my cost per lead?
It doesn’t guarantee improvement. What it does is protect signal quality. If 30–40% of your traffic declines cookies, Basic mode removes that data entirely. Advanced mode allows Google to model performance from aggregated signals. In accounts with steady conversion volume and Performance Max campaigns, that often results in more stable optimisation over time.

What’s the difference between Basic and Advanced Consent Mode?
Basic mode blocks tags completely until consent is granted. Advanced mode allows tags to load but controls how data is stored and used based on consent. Basic mode removes signal from declined users. Advanced mode allows anonymised modelling. Advanced generally supports AI-driven campaigns more effectively.

How do I know if my consent setup is wrong?
Common warning signs include:
• “Consent mode installation out of order” messages
• Multiple tracking scripts in page source
• Tags firing before consent defaults are set
• Broken or shrinking remarketing lists
• Conversion volumes that don’t match reality
Often the issue isn’t that Consent Mode is missing - it’s that it’s sequenced incorrectly.

Should I block scripts until consent is given?
For strict Basic compliance, some plugins physically block scripts. However, if you are running Performance Max or relying on AI bidding, fully blocking scripts reduces modelling capability. A properly implemented Advanced setup allows tags to load while still respecting user consent choices.

Is this something I should review regularly?
Yes. As advertising platforms evolve, signal quality matters more each year. Consent is no longer just about compliance. It’s part of the technical foundation that supports performance marketing. If you’re investing in paid advertising, it’s worth ensuring that foundation is solid.

Author

Neil MacLeod

Technical Director

With over 20 years of experience in building and promoting websites, Neil is a seasoned expert in digital marketing and SEO. Passionate about helping businesses grow through innovative web solutions. Neil has built over 400 websites.

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