Google Consent Mode v2 and enhanced conversions decide whether your Google Ads account can still see what your advertising is actually doing. For a UK business spending anything from £1,000 to £100,000 a month on search, Shopping or Performance Max, these two settings now sit between your website and your bidding algorithms. Get them right and Smart Bidding keeps learning from real enquiries and sales, even when a large share of visitors decline cookies. Get them wrong and your conversion column quietly shrinks, remarketing lists stop growing, and automated bidding starts optimising towards a distorted picture of performance.
This how-to guide walks through what Consent Mode v2 is, how it differs from the original version, why enhanced conversions matter in a consent-first UK market, and how to implement both properly with Google Tag Manager, a consent management platform (CMP) and your CRM. You will find a readiness scoring grid, realistic benchmarks for consent rates and recovered conversions, a week-by-week implementation timeline, a cost table, common mistakes, a 12-point checklist and an anonymised case study — all anchored to UK GDPR, the Privacy and Electronic Communications Regulations (PECR) and current ICO guidance.
What is Google Consent Mode v2? Definition and context
Consent Mode is a Google API that lets your website tell Google’s tags — Google Ads, Google Analytics 4 (GA4), Floodlight and the conversion linker — what each visitor has agreed to in your cookie banner. Instead of simply firing or not firing tags, the tags adjust their behaviour according to the consent state. When a visitor refuses advertising cookies, the Google Ads tag does not set or read advertising cookies, but in “advanced” implementations it can still send a cookieless, aggregate “ping” that Google uses for conversion modelling.
Version 2, which Google made mandatory for advertisers targeting users in the European Economic Area and the UK from March 2024, added two new signals to the original two. The full set is now:
- ad_storage — may advertising cookies be stored and read?
- analytics_storage — may analytics cookies be stored and read?
- ad_user_data — may the visitor’s data be sent to Google for advertising purposes?
- ad_personalization — may the data be used for personalised advertising such as remarketing?
The two new parameters exist because of the EU Digital Markets Act, which designates Google as a “gatekeeper” and requires explicit consent before personal data is combined across services for advertising. Google applied the same requirement to UK traffic. The practical consequence is blunt: if your tags do not send ad_user_data and ad_personalization signals, Google treats the data as lacking valid consent, which restricts remarketing audience building, limits Customer Match and can reduce the conversion data feeding your bidding.
Enhanced conversions are the companion feature. When a visitor converts — submits a form, books a call, completes a checkout — the Google tag collects first-party details the visitor has just given you, such as an email address or phone number, normalises them, hashes them with SHA-256 in the browser and sends the hash to Google. Google matches the hash against signed-in Google accounts to attribute the conversion back to the ad click, even when the original click cookie is missing or blocked. Enhanced conversions for leads extends the same idea to offline outcomes: you upload the hashed details of leads that later became customers from your CRM.
Together, Consent Mode v2 tells Google what it is allowed to do, and enhanced conversions improve the quality of the data where consent exists. Neither is a way around consent; both are ways to measure accurately within it.
Before changing anything, open Google Ads → Goals → Conversions → Diagnostics and the “Consent mode” status in your Google tag settings. If either shows “Not detected” or “Needs attention” for UK traffic, you already know where the leakage is — and you have a baseline to measure improvement against.
Consent Mode readiness scoring — where most UK advertisers sit today
When we review Google Ads accounts for UK SMEs and mid-market organisations, the gaps fall into a predictable pattern. Most businesses have a cookie banner; far fewer have a banner that is wired correctly into Google’s tags. The grid below shows the areas we score in a consent-and-measurement audit, and the risk level we typically see for each.
The pattern is consistent: the visible part (the banner) usually exists, while the invisible part (the order in which the default consent state, the banner and the tags load) is where most implementations fail. A banner that looks compliant but lets the Google Ads tag fire before the default “denied” state is set is both a compliance problem under PECR and a measurement problem, because Google cannot model conversions correctly from inconsistent signals.
The governance column matters more than many marketing teams expect. The ICO has been explicit that “reject” must be as easy as “accept”, and in 2025 it wrote to operators of many of the UK’s most visited websites about non-compliant banners. A Consent Mode project is a natural moment to fix the banner design, the cookie policy and the privacy notice in one pass, rather than treating measurement and compliance as separate workstreams.
Consent Mode v2 and enhanced conversions by the numbers
Exact figures vary by sector, audience and banner design, so treat the numbers below as typical planning ranges for UK websites rather than guarantees. They are useful for sizing the problem before you start.
The first figure is the one that matters most. If half your visitors decline advertising cookies and your implementation is in “basic” mode, Google sees nothing from that half: no clicks matched to conversions, no modelling input, no remarketing. In “advanced” mode, cookieless pings let Google estimate a proportion of those missing conversions. Enhanced conversions then improve match rates among visitors who did consent, particularly across devices and browsers that restrict third-party and even first-party cookies, such as Safari with Intelligent Tracking Prevention.
Basic vs advanced Consent Mode — which implementation should you choose?
Google offers two implementation styles. The choice affects how much data you recover, how much legal review you need and how your tags behave before a visitor has made a choice. Neither is automatically “right”; the decision belongs with whoever owns data protection in your organisation, informed by your marketing team.
Basic Consent Mode
Tags blocked until consent
Advanced Consent Mode
Tags load, behaviour adapts
In basic mode, your CMP blocks Google tags entirely until the visitor accepts. When the visitor declines, nothing is sent. Google still applies a generic conversion model to fill some gaps, but it is less tailored to your account. In advanced mode, the Google tag loads immediately with all four signals defaulting to “denied”. If the visitor declines, the tag sends cookieless pings — containing information such as a timestamp, user agent and referrer, but no advertising cookies — which Google uses to build an advertiser-specific conversion model once the account has enough volume.
Google has historically indicated that advanced-mode modelling needs a minimum volume of traffic and conversions per country and domain before it activates, so a very small account may see limited benefit. That is one reason we often recommend basic mode for low-traffic B2B sites with only a handful of conversions a week, and advanced mode for accounts with steady daily conversion volume.
Whichever you choose, the PECR position is unchanged: you need consent before storing or accessing non-essential information on a user’s device. The Data (Use and Access) Act 2025 introduced new exemptions for some low-risk purposes, such as certain analytics used to improve a service, but advertising cookies remain firmly in consent territory. Take legal advice on the detail and document your reasoning.
The measurement gap — where conversions disappear
To understand why these features matter, it helps to see where conversion data typically leaks in a UK Google Ads setup that has not been updated. The bars below show the share of accounts in which each issue appears as a material contributor to under-reported conversions, based on typical patterns in audits of SME and mid-market accounts.
Some of these leaks are deliberate choices by visitors and should stay leaks: a person who rejects cookies is entitled to that choice, and no implementation should try to circumvent it. Others are purely technical — missing signals, tags firing out of order, conversions that happen in your CRM weeks after the click and never reach Google. Those are the gaps worth closing, because every conversion Smart Bidding cannot see is a conversion it cannot learn from.
The cross-device and offline rows are where enhanced conversions earn their keep. A B2B buyer might click your ad on a phone during a commute, then return on a work laptop two days later to fill in the form. Without a shared identifier, the click and the form look unrelated. With enhanced conversions, the hashed email on the form can be matched to the Google account that clicked, so the conversion is attributed. For a deeper look at how credit is shared across touchpoints, see our guide to Google Ads attribution.
How many UK sites have Consent Mode v2 fully working?
Having a CMP and having a working Consent Mode v2 implementation are not the same thing. In our experience of reviewing UK SME websites that advertise on Google, the proportion with all four v2 signals firing correctly, defaults set before tags, and region-aware behaviour is still a minority.
The remaining majority usually fall into one of three groups. The first has a CMP that supports Consent Mode, but the Google integration toggle was never switched on, so tags behave as if no consent framework exists. The second has the integration enabled but sends only the original two signals, often because the CMP template predates v2. The third has a correct implementation on the main site but not on landing pages built in separate tools — a page builder, a booking system, a payment provider — which is exactly where the conversions happen.
If you recently rebuilt your site, consent configuration is one of the most commonly lost items. Our website redesign and migration guide covers how to inventory tags and tracking before launch so you are not discovering missing conversions a month after go-live.
How to implement Consent Mode v2 and enhanced conversions — step-by-step timeline
For a typical UK business with one main website, Google Tag Manager and a CRM, a careful implementation runs over four to six weeks. Most of that time is testing, review and letting bidding settle rather than configuration. The timeline below is the sequence we follow.
The ordering matters. Setting defaults before mapping choices, and removing hard-coded tags before enabling enhanced conversions, means each stage can be tested in isolation. Trying to do everything in one tag-manager publish makes it very hard to tell which change caused a drop or spike in reported conversions.
If your site handles payments or sensitive enquiries, treat new tags and data layer pushes as code changes that deserve security review. Our web application penetration testing guide explains why third-party scripts are a common route for data leakage and how to scope testing around them.
Measurement readiness gauge — are you ready to rely on Smart Bidding?
Automated bidding strategies such as Maximise Conversions, Target CPA and Target ROAS are only as good as the conversion data they learn from. We use a simple readiness score out of 100 that weights the factors covered in this guide: consent signals (25 points), tag order and coverage (20), enhanced conversions coverage (20), offline conversion import (20) and governance (15).
A score below 50 usually means Smart Bidding is working with a materially incomplete picture: it may be undervaluing campaigns that drive phone or offline sales, over-crediting branded search, or chasing low-quality form fills because those are the only conversions it can see. Between 50 and 75, the fundamentals are in place but offline outcomes or cross-device matching are weak. Above 75, the account has a sound measurement foundation and the conversation can shift to value-based bidding, conversion values by lead quality and profit-based optimisation.
How you use the score matters as much as the number. It is a prioritisation tool, not a certificate. A business with a low score and modest spend may sensibly choose to fix consent signals first and defer CRM integration; a business spending £30,000 a month on lead generation should usually prioritise offline conversion import, because that is where the gap between “form submitted” and “revenue won” is widest.
What does a Consent Mode v2 and enhanced conversions project cost in the UK?
Costs depend on how many domains and conversion points you have, whether a CMP is already licensed, and how much CRM work is needed. The ranges below reflect typical UK market pricing for SMEs and mid-market organisations in 2026, excluding VAT.
| Scope | Typical effort | Indicative one-off cost | Ongoing cost |
|---|---|---|---|
| CMP licence (single domain, SME traffic levels) | Subscription | £0–£100 set-up | £10–£80 per month |
| Consent Mode v2 audit and basic/advanced implementation in GTM | 1–3 days | £600–£2,000 | Periodic checks |
| Enhanced conversions for web (forms and checkout) | 1–2 days | £500–£1,500 | Minimal |
| Enhanced conversions for leads with CRM integration | 3–8 days | £2,000–£6,500 | Monitoring of sync jobs |
| Multi-domain or enterprise implementation with server-side tagging | 2–6 weeks | £6,000–£20,000+ | £50–£300 per month hosting |
Most of the cost sits in testing and integration rather than configuration. A single-site e-commerce business on Shopify or WooCommerce with a reputable CMP can often complete the core work for under £2,500. A B2B organisation with a long sales cycle, a CRM such as Salesforce or HubSpot and multiple lead sources will spend more, but that is also where the return is clearest, because closed-won data lets Google optimise towards revenue rather than enquiries.
Server-side tagging — running a Google Tag Manager server container on Google Cloud, Cloudflare or a managed host — is sometimes sold as a way to “recover” conversions. It has genuine benefits, including better control over what data leaves your site, first-party cookie durability and page performance, but it does not change the consent requirement. Tags behind a server container still need to respect Consent Mode signals, and server-side tagging is best viewed as a governance and resilience upgrade rather than a measurement shortcut.
Benchmarks and KPIs to track after implementation
Once both features are live, track a short set of indicators so you can tell whether the implementation is working and whether bidding is benefiting. These are the benchmarks we see in well-configured UK accounts after the stabilisation period.
Healthy post-implementation benchmarks
Two of these deserve particular attention. The advertising consent rate is not a target to maximise at any cost — dark patterns that push it higher create regulatory risk and erode trust. A fair banner that achieves a consent rate somewhere in the 40–65% range is normal for UK audiences, and anything much higher with a compliant design is a good result. The enhanced conversions coverage figure in Google Ads diagnostics shows what proportion of conversions arrived with usable user-provided data; if it is low, the usual cause is a data layer variable that is empty on the confirmation page or a form that changed field names.
Keep the monitoring lightweight. A monthly review of these nine indicators, plus a quick check after any website release, catches most regressions before they affect bidding. If you are building reporting dashboards that combine Google Ads, GA4 and CRM data, structure them around these same KPIs so the marketing and finance teams are looking at one version of the truth.
Common Consent Mode v2 and enhanced conversions mistakes to avoid
Most problems we fix are not exotic. They are small configuration slips with large consequences for both compliance and measurement.
- Tags firing before the default consent state. If the Google tag loads on an “All Pages” trigger and the CMP’s default runs later, the first hit of every session goes out without consent signals. Use the Consent Initialization trigger for defaults.
- Only sending the original two signals. Older CMP templates and hand-written gtag snippets often set ad_storage and analytics_storage only. Without ad_user_data and ad_personalization, remarketing and audience features are restricted for UK and EEA traffic.
- Collecting enhanced conversions data from the wrong field. Automatic detection sometimes grabs a newsletter field in the footer or a staff email in the page template. Use explicit data layer variables and verify the values in preview mode.
- Double-counting conversions. Importing GA4 key events and running a native Google Ads conversion tag for the same form, both set as primary, inflates conversions and skews bidding. Pick one primary source per action.
- Forgetting the landing-page builder and booking widget. Unbounce, Instapage, Calendly embeds and payment pages often sit outside your main GTM container and need their own consent configuration.
- Treating a modelling uplift as real-world growth. Modelled conversions are estimates. If reported conversions rise after implementation, check whether it reflects recovered measurement rather than more customers before scaling budgets.
- Changing bid strategies during the learning period. Making major bidding changes in the same fortnight as a tracking change makes it impossible to diagnose what happened. Stabilise first, optimise second.
- Not updating the privacy notice. Enhanced conversions share hashed personal data with Google. Your privacy notice should explain this, name Google as a recipient and state your lawful basis.
Never configure tags to ignore a visitor’s refusal, or set consent to “granted” by default for UK traffic to boost numbers. Beyond the PECR and UK GDPR exposure — the ICO can issue fines and enforcement notices — Google’s EU user consent policy requires valid consent, and breaches can lead to restrictions on your account. Accurate measurement within consent is the only sustainable route.
Consent Mode v2 and enhanced conversions checklist — the 12-point essentials
Use this checklist to sign off an implementation, or to run a quick health check on an existing setup every quarter.
- All Google tags (Ads, GA4, Floodlight, conversion linker) are managed through a single GTM container or a single gtag configuration, with no hard-coded duplicates.
- A Consent Mode v2-compatible CMP is installed, ideally Google-certified, with “Reject all” equally prominent on the first layer.
- Default consent for ad_storage, analytics_storage, ad_user_data and ad_personalization is “denied” for UK and EEA visitors and is set via the Consent Initialization trigger.
- Banner choices update all four signals on the same page view and persist for returning visitors.
- The chosen mode (basic or advanced) is documented, with the reasoning signed off by whoever owns data protection.
- Non-Google marketing tags (LinkedIn, Meta, Microsoft Advertising, TikTok) have explicit consent requirements in GTM.
- Customer data terms are accepted in Google Ads and enhanced conversions for web are enabled for each relevant conversion action.
- User-provided data (email at minimum) is pushed to the data layer on conversion and mapped in the Google tag, verified in preview mode.
- For lead generation, GCLID and hashed email are stored in the CRM and qualified or won stages are uploaded to Google Ads at least daily.
- Each conversion action has a clear primary or secondary status, a sensible counting setting and a named owner.
- Google Ads diagnostics show “Excellent” or “Good” enhanced-conversion status and no consent-mode warnings for UK traffic.
- The privacy notice and cookie policy describe Consent Mode behaviour, enhanced conversions and Google as a data recipient.
Microsoft Advertising has its own Universal Event Tracking consent mode and enhanced conversions equivalent. If you run campaigns on Bing as well as Google, configure both from the same CMP categories so your measurement and compliance stay consistent across platforms.
Mini case study — a Leeds professional services firm
A 45-person professional services firm in Leeds was spending around £9,000 a month on Google Ads, mainly search campaigns for high-value advisory enquiries, with Target CPA bidding. Over six months the reported cost per lead had risen by roughly 40%, while the partners felt the volume of genuine enquiries was broadly flat. The marketing manager suspected that changes to the website, a new cookie banner and an increasing share of Safari and iPhone traffic were all affecting measurement, but could not pin down how.
The audit found three problems. The CMP was installed, but its Google integration had been left switched off after a site rebuild, so the Google Ads tag fired on every page regardless of consent — a compliance issue as well as a measurement one. The contact form on a separate booking page had no conversion tag at all. And the firm’s CRM held a clear record of which enquiries became fee-earning clients, but none of that information ever reached Google Ads, so the bidding treated a spam enquiry and a six-figure engagement identically.
Over five weeks the firm moved to a compliant banner with equal-prominence buttons, set Consent Mode v2 defaults correctly in advanced mode (after review by its data protection lead), consolidated tags into one container, enabled enhanced conversions on both forms and set up a daily upload of “qualified” and “instructed” stages from the CRM. Bidding was switched to optimise towards qualified leads once enough volume had accumulated, roughly eight weeks later.
“We assumed we had a cost problem. We actually had a visibility problem. Once Google could see which enquiries turned into real work, the campaigns started favouring the searches that brought us clients rather than the ones that brought us forms.” — Marketing manager, Leeds professional services firm
The firm’s takeaway was not a headline percentage but a change in what it could trust. The reported conversion count fell slightly once spam and duplicate conversions were removed, yet the share of those conversions that became qualified opportunities rose, and the partners now review Google Ads performance using pipeline value rather than form fills. The cookie banner, meanwhile, now reflects what the website actually does — which was the original compliance point all along.
At-a-glance summary — Consent Mode v2 and enhanced conversions
| Topic | Key fact |
|---|---|
| What Consent Mode v2 does | Passes visitors’ consent choices to Google tags so they adapt their behaviour |
| The four signals | ad_storage, analytics_storage, ad_user_data, ad_personalization |
| Who must implement it | Advertisers using Google Ads or GA4 audiences with UK or EEA visitors |
| Basic mode | Tags blocked until consent; nothing sent on refusal |
| Advanced mode | Tags load with denied defaults; cookieless pings support advertiser-specific modelling |
| Enhanced conversions for web | Hashed first-party data from forms or checkout improves conversion matching |
| Enhanced conversions for leads | Hashed CRM data links offline outcomes back to ad clicks |
| Hashing | SHA-256, applied after normalisation, before data leaves the browser or server |
| UK legal basis | PECR consent for non-essential cookies; UK GDPR for personal data processing |
| Typical UK advertising consent rate | Roughly 40–65% with a fair, equal-prominence banner |
| Typical implementation time | 4–6 weeks including testing and bidding stabilisation |
| Typical SME cost | £1,100–£3,500 for web; more with CRM or server-side tagging |
| Most common failure | Default consent state set after tags have already fired |
| What it cannot do | Override a visitor’s refusal or restore remarketing for non-consenting users |
How Cloudswitched helps with Google Ads measurement
Cloudswitched manages Google Ads campaigns for UK businesses and treats measurement as part of campaign management rather than a separate technical project. Our team can audit your consent and conversion setup, implement Consent Mode v2 and enhanced conversions in Google Tag Manager, connect your CRM so bidding learns from real outcomes, and document the configuration so your data protection lead can sign it off. Because we also provide web development and IT services, we can work directly on the website, the tag container and the CRM integration without handing off between suppliers.
Get your Google Ads tracking consent-ready
Talk to our PPC team about a consent and conversion tracking audit for your Google Ads account.
Talk to us about Google Ads managementFrequently Asked Questions
Is Google Consent Mode v2 a legal requirement in the UK?
Consent Mode v2 itself is a Google requirement rather than a law. The legal requirement comes from PECR, which says you need consent before storing or reading non-essential cookies, and UK GDPR, which governs personal data processing. Google made Consent Mode v2 mandatory from March 2024 for advertisers who want to use measurement, remarketing and audience features with UK and EEA traffic. In practice, if you advertise on Google and have UK visitors, you need both a compliant consent banner and a working Consent Mode v2 implementation.
What happens if I do not implement Consent Mode v2?
Without valid v2 signals, Google treats UK and EEA traffic as lacking consent for advertising data use. Remarketing lists stop growing from that traffic, Customer Match and some audience features are restricted, and conversion measurement and modelling become less complete. Smart Bidding therefore learns from a thinner, less representative data set, which can push up cost per acquisition. There is also the separate compliance risk if your tags are setting cookies without consent.
Should I choose basic or advanced Consent Mode?
Advanced mode generally recovers more conversion insight because cookieless pings feed an advertiser-specific model, which suits most e-commerce and lead-generation accounts with steady conversion volume. Basic mode is simpler to justify legally because no Google tag loads until consent is given, and it suits regulated sectors or low-traffic sites where modelling would have limited data anyway. The decision should be made with your data protection lead and documented, as it affects what your privacy notice must explain.
Are enhanced conversions compliant with UK GDPR?
Enhanced conversions can be used compliantly, but they do involve sharing personal data, albeit hashed, with Google. Hashing is pseudonymisation rather than anonymisation, so UK GDPR still applies. You need a lawful basis, a privacy notice that explains the processing and names Google as a recipient, and enhanced conversions should only operate where the visitor has given the relevant advertising consent. Google acts under its own data processing terms, which you accept in the Google Ads interface.
How much conversion data does Consent Mode v2 recover?
It depends heavily on your consent rate, traffic volume and implementation. Google states that conversion modelling can recover a meaningful share of the conversions lost when visitors decline cookies, but the exact uplift varies by account and is not guaranteed. Small accounts may not reach the volume thresholds needed for advertiser-specific modelling at all. Treat modelled conversions as estimates and judge success by whether reported conversions align better with your CRM and finance data.
Do I need a Google-certified CMP?
Google maintains a list of certified consent management platforms and strongly recommends using one for EEA and UK traffic; for publishers serving Google ads it is a requirement. For advertisers, a certified CMP is the simplest way to ensure the four signals are sent correctly and kept up to date as Google changes its requirements. Building a custom integration is possible, but it adds maintenance responsibility and testing overhead.
Can I use enhanced conversions without Google Tag Manager?
Yes. Enhanced conversions can be set up with the gtag.js library directly in your site code, through some e-commerce platforms’ native integrations, or via the Google Ads API for offline and lead uploads. Tag Manager is usually the most maintainable option because it centralises consent checks, data layer variables and testing tools, but the best route depends on how your website is built and who maintains it.
Will Consent Mode v2 change my reported conversions?
Often, yes. Conversions may rise as modelled conversions appear and enhanced conversions improve matching, or fall if the audit removes duplicates, spam and tags that were firing without consent. Both outcomes can indicate a healthier setup. Annotate the change date, compare against CRM and sales data, and avoid big bidding or budget changes for two to six weeks while Smart Bidding adjusts to the new data.
How do enhanced conversions for leads work with a CRM?
When someone submits a form, you store the GCLID and the email address (or its hash) against the new lead in your CRM. As the lead progresses — qualified, opportunity, won — you upload those stages to Google Ads with the hashed email, either through a native connector such as HubSpot or Salesforce, a scheduled file import, or the Google Ads API. Google matches the hash to the original click so bidding can optimise towards leads that actually become customers.
Does the Data (Use and Access) Act 2025 remove the need for cookie consent?
No, not for advertising. The Act introduces exemptions from the PECR consent requirement for certain low-risk purposes, such as some analytics used to improve a website or service, subject to conditions like giving users a simple way to object. Advertising cookies and tracking for marketing purposes still require consent. Check the ICO’s current guidance as the provisions come into force and take legal advice on how they apply to your analytics setup.
How often should we audit our consent and conversion tracking?
A light-touch quarterly check against the 12-point checklist is a sensible minimum, plus a targeted test after any website release, CMP update, CRM change or new landing-page tool. Tag configurations drift quietly as sites evolve, and many of the problems in this guide appear months after an implementation that was originally correct.
Related reading
Explore more guides from the Cloudswitched blog on measurement, website quality and secure data handling:
Make every Google Ads conversion count — within consent
Cloudswitched’s Google Ads team can review your consent setup, enhanced conversions and CRM integration, and help your bidding learn from the outcomes that matter to your business.
Explore Google Ads management
Cloudswitched
London-based managed IT services provider offering support, cloud solutions and cybersecurity for SMEs.
