We audit analytics setups fairly often, and it's rare to find one that's fully correct. Duplicate tags, missing conversions, no consent handling, or Universal Analytics code still sitting there years after it stopped collecting anything.
This post covers the piece that causes the most confusion right now: Consent Mode v2.
What Consent Mode actually does
When someone visits your site, a cookie banner asks whether they accept analytics and advertising cookies. Consent Mode is the bridge between that banner and your Google tags.
- If the visitor accepts, Google tags work normally.
- If the visitor declines, the tags still send limited, cookieless signals ("pings") without storing identifiers.
Google then uses those pings, together with data from people who did accept, to model the missing conversions. Your reports become more complete than if you simply blocked everything for people who said no.
Version 2 added two new consent signals, ad_user_data and ad_personalization, which Google requires for advertisers who use data from European users for ads measurement and personalisation.
Basic vs Advanced mode
Basic: Google tags don't load at all until consent is given. Simpler and more privacy-conservative, but you lose more data.
Advanced: Tags load immediately with consent defaulting to "denied", and send cookieless pings until the user decides. Better modelling, slightly more complex.
For most small businesses in India without EU customers, basic mode is a perfectly reasonable choice. For anyone running Google Ads to Europe, advanced mode is usually worth it.
Setting it up step by step
- Pick a consent banner that supports Google Consent Mode v2. Many consent management platforms (CMPs) have free plans for small sites, and several are Google-certified.
- Set default consent states before any Google tag fires. In Google Tag Manager, use the consent initialisation trigger.
- Update consent when the visitor makes a choice. A good CMP does this automatically.
- Check in Tag Assistant. Open your site with Google Tag Assistant and confirm the consent states change when you click accept or decline.
- Look at GA4's admin. Under data collection settings, GA4 shows whether consent signals are being received.
Common mistakes
- Loading GA4 twice, once hardcoded in the theme and once through Tag Manager. Your pageviews will be doubled.
- Banner loads after the tags. Then tags fire before consent defaults are set.
- No conversions marked. GA4 tracks events, but you need to mark the ones that matter (form submissions, purchases, calls) as key events.
- Tracking the thank-you page by URL when the form actually submits via AJAX and never loads a new page.
Keep it simple
Analytics should answer a few business questions: how many people visit, where they come from, and how many become enquiries or customers. Get those three things accurate before adding anything fancier. A clean, correct setup with five events beats a messy one with fifty.
