Consent Mode v2 setup: mandatory for your Google Ads data

If your audience sits in the EU and you run Google Ads, Consent Mode v2 isn’t a nice extra — it’s mandatory. Without it your conversion data falls away and your remarketing lists run dry. Setting it up is no black art once you know the order: pick a CMP, integrate it cleanly into Google Tag Manager, test the consent status. That’s exactly what we’ll walk through here — including the CMPs I use in client projects myself.

Consent Mode v2 is Google’s standard for passing your visitors’ cookie decision on to Google services. Your cookie banner — the CMP, or consent management platform — collects the consent. Consent Mode translates the answer into signals that Google Ads and GA4 understand and respect.

In practice it sends four consent signals to Google:

ad_storage — may advertising cookies be set and read
analytics_storage — may analytics cookies (GA4) be set
ad_user_data — may user data be sent to Google for advertising purposes
ad_personalization — may that data be used for personalised advertising (remarketing)

The last two are the “v2” part. Since March 2024 Google requires these signals for traffic from the EEA and the UK. When they’re missing, you get exactly what nobody wants:

Remarketing lists stop filling up — your audiences in Google Ads shrink or stay empty.
Conversions from users without a valid signal never arrive in the account, or arrive in a form you can’t use.
Smart Bidding gets less data and optimises accordingly — you pay the same click price for dumber bids.

Basic vs Advanced

Consent Mode v2 comes in two flavours, and the difference matters:

Basic: Google tags only load after consent. Anyone who declines simply doesn’t exist for Google — no cookies, no pings, no data. The strictest and simplest reading.
Advanced: the tags always load, but run cookieless without consent. They send anonymised pings from which Google models conversions — so a share of the “lost” conversions comes back into the account statistically.

Advanced gets you measurably more data, but it’s the more contested option from a privacy law point of view. I’m not a lawyer: which variant is defensible for you is something you settle with your data protection officer or your solicitor, not with a blog article. I’ve written up what GDPR-compliant conversion tracking looks like as a whole here: GDPR-compliant conversion tracking.

Mandatory in the EU — and what about California and Brazil?

What counts isn’t where your company sits, it’s where your users sit. Audience in the EEA or the UK means Consent Mode v2 is mandatory, full stop. And the direction of travel is the same everywhere: Google is extending its consent requirements to regimes like California (CCPA/CPRA) and Brazil (LGPD) too. Advertise in those markets and a clean consent setup does the same homework once, instead of retrofitting three times later.

2. Picking the right CMP: what I actually use

The CMP is the tool that collects consent and sets the consent signals. No CMP, no Consent Mode — which is why this decision comes first. In my projects it comes down to three setups.

Usercentrics — my favourite

When I get a free choice, I take Usercentrics. For me it’s the best CMP on the market: clean Consent Mode v2 support, granular settings, geo rules for different legal jurisdictions and a decent GTM integration. Not the cheapest option — but the one that creates the least friction on a demanding setup with multiple languages, multiple domains and different markets.

e-recht24 — pragmatic and solid

The second solution I work with is the consent manager from e-recht24. It comes out of the German legal ecosystem, it’s pragmatically built, and for a lot of websites — especially in the WordPress world — it’s entirely enough. If you’re already using e-recht24 legal texts, you get a coherent package here.

Hand-built — like on my own site

Third option: build the banner yourself. That’s what runs on my German site — my cookie banner is hand-coded. Upside: full control over design and load time, no licence costs, no third-party script. The price: you implement the consent API (gtag('consent', ...)) yourself, keep it current, and carry the responsibility for setting default and update signals correctly. Only worth it if you have developer resources — otherwise buy the problem away.

Webflow

On Webflow sites I use Usercentrics as well. It’s wired in identically through the official GTM template, so there’s no reason for a special case.

Short version of which CMP fits where:

Demanding setup, several markets, budget available → Usercentrics
WordPress, e-recht24 legal texts already in use → e-recht24
Webflow → Usercentrics here too
Your own codebase plus developers in-house → build it yourself

The order is always the same, whichever CMP you pick. Stick to it and you’re through in an afternoon.

Step 1: choose and embed the CMP

Decide based on the list above and embed the CMP as early in the source as you can — it has to be running before any other tag fires. While you’re there, check three things:

The CMP sets all four consent signals to denied by default before the user has decided.
Your banner’s cookie categories map cleanly onto the signals (marketing → ad_storage, ad_user_data, ad_personalization; statistics → analytics_storage).
The banner blocks Google tags until the user decides (Basic), or lets them run cookieless only (Advanced) — depending on which variant you agreed with your lawyer.

Step 2: the GTM integration

Google Tag Manager is the control room: consent signals and your Google Ads and GA4 tags all meet here. If your Google Ads tracking doesn’t run through GTM yet, start there — set up Google Ads through Google Tag Manager — and come back afterwards.

The integration itself:

Use your CMP’s official GTM template from the template gallery (Usercentrics and e-recht24 both ship one) and fire it on the Consent Initialization trigger — that one is guaranteed to run before every other tag.
The template sets the default status (denied) and, after the banner interaction, sends the update (granted/denied) to all tags.
Turn on the consent overview in GTM (Admin → Container Settings) and walk through every tag. Google tags come with the consent check built in; third-party tags often need additional consent assigned by hand.

If you’d rather not click a container together by hand, my GTM configurator lets you assemble a ready-made container and import it straight away. It’s on my German site: GTM configurator (in German) — the JSON it produces is language-neutral.

The step almost everyone skips — and the reason “but we do have a cookie banner” so often still means broken tracking. Without a test, your consent setup is a guess. Here’s how to check it:

GTM preview mode: open the consent tab in Tag Assistant. On page load all four signals must read denied (default); after clicking “Accept” they must read granted (update). If the default status is missing or arrives late, tags are firing before consent — which is exactly what must not happen.
Test both paths: accept everything once, decline everything once (an incognito window helps). On decline, no Google tag may fire in Basic mode; in Advanced mode only cookieless pings may go out.
Look at the network requests: in the requests to Google, the gcs and gcd parameters show which consent status is actually being transmitted. That’s the truth — not what the banner claims.
Check the aftermath: a few days later, look in Google Ads to see whether conversions are coming in normally again and the remarketing audiences are refilling.

For a quick first impression of whether your tracking measures cleanly at all, there’s my free tracking check: Tracking-Check (in German).

The bottom line

Consent Mode v2 isn’t a nice-to-have. It’s the precondition for your Google Ads account working with usable data at all in the EU. The take-aways:

Audience in the EU → Consent Mode v2 is mandatory. And if you’re advertising towards California or Brazil, the same setup solves those requirements too.
Basic is the strictest variant; Advanced pulls data back through modelling. Which one fits you is a decision for your data protection officer, not your gut.
CMP choice from my own practice: Usercentrics when it has to be flexible, e-recht24 as the pragmatic option, Usercentrics on Webflow too, hand-built only with developer resources.
The order is fixed: embed the CMP → integrate through Consent Initialization in GTM → test the consent status in Tag Assistant. Without the testing step, everything before it is hope.

Set up cleanly, you notice the difference in the account straight away: audiences fill up again, conversions come in, Smart Bidding has something to eat.

If you’re not sure your consent setup really measures cleanly — or whether conversions are quietly falling away right now — write to me. I’ll look at your tracking setup and tell you honestly what’s missing and what’s fine.