My site is only for Romania. Does Consent Mode v2 concern me?

Yes. Romania is in the EEA, so all your visitors are covered by the requirement. Without v2 signals, Google Ads stops building audiences and flags conversions as affected.

Does Consent Mode replace the cookie banner?

No. The banner (CMP) obtains the choice; Consent Mode passes it to Google tags. You need both, wired correctly.

Does modelling "invent" conversions?

It statistically estimates what happened in unconsented traffic based on consented traffic, and marks the figures as modelled. It does not add people; it fills in aggregates — and only above volume thresholds.

Consent Mode v2, explained: a banner without signals is worth

The situation

You have a cookie banner. It is there, it looks good, it can be accepted and refused. And yet Google Ads shows a warning on conversions, remarketing no longer adds European visitors to audiences, and GA4 shows a drop nobody can explain. The banner is not the problem. The problem is that the banner does not talk to the tags. That is Consent Mode: the language in which the banner tells Google what the visitor answered.

Consent Mode is a Google mechanism through which tags (the Google tag, GA4, Google Ads, Floodlight) adapt their behaviour to the user's consent. It is not a banner; it is the layer under the banner.

Version 2 became mandatory in March 2024 for anyone who wants to use Google's advertising features — conversion measurement with user data, remarketing, audiences — for visitors from the European Economic Area and the UK. Without v2 signals, Google Ads stops building audiences from European traffic and flags conversion measurement as affected.

The four signals

Signal	What it controls	New in v2
`analytics_storage`	Analytics cookies (GA4): sessions, returning users	no
`ad_storage`	Advertising cookies: conversion measurement, click IDs	no
`ad_user_data`	Sending user data to Google for advertising purposes	yes
`ad_personalization`	Personalised advertising, remarketing, audiences	yes

Each signal has two values: granted or denied. The banner must set all four, at two moments: the default, before any tag runs — usually denied for EEA visitors — and the update, as soon as the visitor chooses.

Basic vs Advanced

There are two ways to implement it, and the choice matters:

Basic: until consent, Google tags do not load at all. If the user refuses, nothing is sent. Simple, easy to explain legally, but Google receives no information about visitors who refused — so it cannot model.
Advanced: Google tags load before consent, but with the signals set to denied. In that state they neither set nor read cookies; they only send pings without identifiers. When the user accepts, the tags switch to full behaviour.

Advanced mode is what enables behavioural modelling.

Modelling: what you recover and what you do not

When 40% of visitors refuse, GA4 and Google Ads do not see their conversions. With Consent Mode Advanced, Google receives the anonymous pings and uses the behaviour of visitors who accepted to estimate the conversions and sessions of those who refused. The figures appear in reports marked as modelled.

Two things to know:

Modelling has volume thresholds: GA4 requires a minimum daily number of events with and without consent, over a sustained period, before it starts. A site with 200 visits a day may get no modelling at all; that is normal, not a fault.
Modelling is a statistical estimate, not data recovery. You will not see which pages a particular refusing user visited. You see aggregates.

The choice between Basic and Advanced is not only technical — it is a decision about how far you go before consent. Make it with your legal adviser. Both variants are accepted by Google.

Where the CMP comes in

The CMP (Consent Management Platform) is the banner with a brain: it remembers the choice, applies it on every page, detects the region and, crucially, sends the Consent Mode signals. Google runs a programme of certified partner CMPs that have the integration ready; in GTM, many appear as templates in the community gallery and place the default command before all tags on their own.

If your banner is a random plugin or something written in-house, it is very likely to show buttons but send no signal at all. You have the (partial) legal tick and zero effect on measurement.

How to verify it works

Tag Assistant / Preview in GTM: open the site, pick an event on the left and look at the Consent tab. You see the state of each signal "on page load" and "on update" and, on each tag, whether it was affected by consent. Refuse in the banner and check the signals are denied; accept and check they become granted.
GA4: in Admin, the data collection section has a consent settings area showing whether the property receives signals and whether modelling is active.
Google Ads: under Goals → Conversions, the diagnostics area shows the Consent Mode status for conversion actions and for EEA traffic.
Browser console: in Network, GA4 collect requests carry a gcs parameter encoding the consent state — useful for a developer.