Google Ads conversion tracking, GA4 and consent mode in the UK
A plain-English map of tags, consented measurement and lead imports so you can optimise bids without breaking privacy expectations.
If conversion data is patchy, automated bidding optimises toward noise. In the UK, cookie banners and PECR mean you also cannot fire every tag at every visitor and hope for the best. You need one definition of a lead, a tag that respects consent, and a way to tell Ads which of those leads were worth having. This sits underneath any Google Ads account we would be willing to scale.
Define one primary conversion per funnel stage
- Primary: qualified lead or purchase. Secondary: micro-conversions like brochure downloads.
- Avoid double-counting the same lead across GA4 and Google Ads imports — pick a source of truth.
Consent-aware tagging
Agree the default with whoever owns privacy for the business: what runs before a choice, and what waits for a yes. Technically, Consent Mode tells Google’s tags about that choice so measurement can model some gaps when people decline, without you storing more than the banner allows. Test the form after accepting and after rejecting. A conversion that only fires for people who never see the banner is not a conversion strategy.
Close the loop when the lead is not the sale
For many UK service businesses the website enquiry is the start. Import a later status — qualified, quoted, won — from the CRM or a simple spreadsheet on a schedule you will keep. Label the value if you know it. Bidding can then prefer the enquiries that turn into work, which is the point of the lead-quality article later in this series. Until that import exists, do not let the account chase the cheapest form fill.
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Questions people ask
What should my primary Google Ads conversion be?
A lead or sale you would actually want: a completed enquiry, a booked call, or a purchase. Button clicks and page views can be secondary. If everything is primary, bidding optimises toward the easiest one.
Do I need Consent Mode in the UK?
If you use Google tags and a cookie banner, you need a setup that respects the choice people make. Consent Mode is the usual way to pass that choice to Ads and Analytics. Get the legal default agreed before you wire the tags.
Why do GA4 and Google Ads show different lead numbers?
They often count different events, or the same form twice. Pick one source of truth for bidding — usually the Ads conversion or an imported qualified lead — and treat the other report as a check, not a second target.
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