Google Ads Conversion Tracking Broken? Consent Mode v2, Enhanced Conversions and GA4 Fixes

The Monday message usually reads something like this: "Spend is normal, clicks are normal, conversions went from 40 a day to four. Did Google break something?" Almost every time, Google didn't. Somebody installed a new cookie banner, moved the thank-you page, or let a developer "tidy up" Google Tag Manager on Friday afternoon.

It still hurts. When Google Ads conversion tracking is not working, Smart Bidding bids blind within days. Target CPA throttles spend because nothing seems to convert, and the longer the gap, the more bad history the algorithm learns from.

This guide follows the order we work these tickets in: what Google changed, a quick check that the data is really broken, the causes ranked by frequency, and the fixes with real menu paths.

What changed in Google Ads conversion tracking in 2025–2026?

A lot, mostly quietly.

Consent Mode v2 went from warning to enforcement

Google added the ad_user_data and ad_personalization parameters to Consent Mode in December 2023, alongside the original ad_storage and analytics_storage. From 21 July 2025, Google began disabling personalised ads, remarketing and conversion tracking for advertisers whose EU sites didn't comply with its EU user consent policy, as PPC Land reported on 30 July 2025.

The damage often surfaces months later. In April 2026, PPC Land wrote up a case shared by Mike Teasdale of Harvest Digital: a client's conversions dropped 90% overnight with no account changes. The banner collected consent but never passed it to Google's tags.

"The answer was Consent Mode V2."— Mike Teasdale, Founder and Planning Director, Harvest Digital, as quoted by PPC Land, April 2026

After the fix, roughly 40% of the lost attribution came back through modelling. The rest was gone. One account isn't a study, but it matches what we see: you can repair the pipe, not refill the history.

Google Signals no longer decides what Ads can use

From 15 June 2026, the Consent Mode ad_storage state became the single control for advertising data flowing from linked Google Analytics properties into Google Ads, according to PPC Land's April 2026 coverage of Google's Help Center notice.

Enhanced conversions became one switch

Google's help page on the 2026 settings update explains that enhanced conversions for web and for leads now run as a single feature with an on/off switch, and Google Ads now accepts user-provided data from tags, Data Manager and API connections at once. Existing users were migrated automatically. The setting lives under Goals › Settings, in the Customer data use panel.

Offline imports moved to the Data Manager API

On 15 June 2026, offline conversion imports and enhanced conversions for leads uploads were moved to the Data Manager API and blocked in the Google Ads API, per Google's enhanced conversions for leads documentation. A CRM sync built on the old API may have simply stopped in June.

New status labels and first-party tag serving

In July 2026 Google replaced the old statuses (Inactive, No recent conversions, Other) with Active, Needs attention, Misconfigured, Awaiting conversions and Removed. And since May 2025, Google tag gateway for advertisers lets you serve Google tags from your own domain through a CDN such as Cloudflare. Google reported an 11% signal uplift for advertisers using it (April 2025 data).

Is your tracking broken, or just reporting differently?

Before you rip anything out, check the numbers are actually wrong. Many "broken tracking" tickets are two systems counting different things.

Google Ads credits a conversion to the date of the ad click. GA4 credits it to the date the conversion happened. Google's GA4 import documentation also notes that imported key events can take up to 24 hours to appear, that conversion actions created in GA4 are Secondary by default, and that the "Conversions" column only counts Primary actions while "All conversions" includes Secondary ones.

A second check is your conversion rate against peers. A lead-gen account at 30% when its industry averages 6% is almost certainly double counting; one at 0.4% is probably missing a tag. Clinics that count calls are a special case, which our dentist PPC guide covers.

A 20-minute diagnostic for Google Ads conversion tracking not working

Work through these in order. Each step finds the fault or rules out a whole category.

1. Read the status columnGo to Goals › Summary and look at the Status column for every Primary action. Click the status, then View details or View all issues. "Misconfigured" means recording has stopped. "Awaiting conversions" means nothing in the last 7 days, which is normal only for actions under 48 hours old or paused campaigns.
2. Find the date it brokeSegment the Conversions column by day for the last 60 days. A cliff on one date points to a site or tag change. A slow slide points to consent, gclid loss or coverage.
3. Check the change history on both sidesThe Change history page in Google Ads, the Versions tab in Google Tag Manager, and your developer's deploy log. Ask about banner, checkout, CRM and form changes too.
4. Open the Diagnostics tabIn Goals › Summary, select the Diagnostics tab and open the enhanced conversions card. Check coverage, match rate (LOW below 15%, HIGH above) and alerts.
5. Test a real conversion in Tag AssistantConnect your site at tagassistant.google.com and complete a test lead or purchase. Confirm the conversion fires once, with the right ID and label, a value and a transaction ID.
6. Test consent both waysRepeat the test rejecting, then accepting, cookies from a UK or EU VPN. The Consent tab should show ad_storage, analytics_storage, ad_user_data and ad_personalization as denied, then switching to granted on accept.
7. Follow the gclidAdd ?gclid=test123 to a landing URL and walk through to the thank-you page. If the parameter vanishes after a redirect or form step, Google can't tie the conversion to the click.
8. Count your Primary actionsList every action marked Primary in the goal your campaigns use. If a GA4 "purchase" import and a Google Ads purchase tag are both Primary, you're counting each sale twice.

How symptoms usually map to causes:

Root causes, ranked by how often we see them

This ranking comes from our own audits of lead-gen and e-commerce accounts in the US, UK, Canada and Australia. It's practitioner experience, not a published study.

1. The site changed and the tag didn't

Still the most common by a distance. A new theme, a page builder update, a checkout app, a form plugin that now submits by AJAX instead of loading a thank-you URL. The GTM trigger was "Page URL contains /thank-you" and that page no longer exists.

2. Consent Mode is installed but doesn't actually work

The banner shows, the user clicks Accept, and nothing changes in the tags. Usually the CMP sets a default of denied but never sends the update command, or the Google tag loads before the default is set, or a custom banner only handles ad_storage and leaves out the two v2 parameters. A US, Canadian or Australian brand selling into the UK and Europe is covered for that traffic too.

3. Double counting

Less dramatic, more expensive. GA4 key events imported as Primary beside the native tag; a purchase tag firing on every reload of the confirmation page with no transaction ID; lead forms counted "Every". The account looks great; revenue doesn't follow.

4. The gclid gets lost

Auto-tagging switched off in Account settings, a redirect that drops query strings, a booking widget on a third-party domain, or a CRM form that never stores the gclid. Without it, an offline conversion can't be matched unless enhanced conversions finds the user through hashed email or phone.

5. Enhanced conversions with empty fields

The setting is on, but the data layer sends blank email fields, or the address is missing country or postal code. Google's tag diagnostics documentation lists the error codes you'll see: e0 for failed validation, e2 for hashing failure, e3 when the page isn't served over HTTPS, and "tv.1" with nothing after it for an empty field.

6. Offline import plumbing

Jobs failing after the June 2026 API change, time zones missing from Conversion Time, or monthly batches that let clicks age past 90 days. Google suggests waiting 4–6 hours before the first upload to a new action.

7. Nothing is broken

Seasonality, a landing page outage or a disapproval can drop conversions while tracking works fine. If clicks fell too, start with the campaign. Our Performance Max troubleshooting guide covers the campaign-side causes.

How to fix Google Ads conversion tracking, step by step

Do these in order. Fixing enhanced conversions on top of a tag that doesn't fire is wasted effort.

1. Pick one source of truth per conversionFor each business outcome (purchase, qualified lead, booked call), decide whether the native Google Ads tag or a GA4 import counts it. Set that one as Primary and everything else as Secondary, under Goals › Summary. We usually prefer the native tag for purchases and offline imports for leads.
2. Rebuild the trigger on the real eventIn GTM, fire the conversion on the data layer event your checkout or form actually pushes (a purchase event with transaction_id, value and currency, or a form success event), not on a URL that can change. Set Count to "One" for leads and "Every" for purchases.
3. Set up Consent Mode v2 properlyUse a Google-certified CMP such as Cookiebot, OneTrust, Osano or Sourcepoint. Set defaults to denied for EEA and UK visitors before any Google tag loads, then send an update on the user's choice covering all four parameters. If legal agrees, choose advanced mode: Google says advanced consent mode recovers about twice as many conversions as basic.
4. Turn on enhanced conversionsGoals › Settings › Customer data use › "Turn on enhanced conversions", then Agree and save. Pass hashed email and phone from the conversion page; addresses need first name, last name, postal code and country.
5. Protect the gclidConfirm auto-tagging is on under Admin › Account settings. Store the gclid (plus gbraid and wbraid) in a hidden form field and in your CRM against the lead. Fix any redirect that drops parameters.
6. Move offline uploads to Data ManagerConnect your CRM through Tools › Data manager, or ask your developer to switch to the Data Manager API. Upload at least daily, as Google recommends for Smart Bidding, and include a time zone in every Conversion Time value.
7. Consider Google tag gatewayIf you're on Cloudflare, it's close to a one-click change that serves the tag from your own domain. It can reduce signal loss from script blockers, though it won't fix a broken trigger.
8. Protect Smart Bidding while data recoversFor a short outage with a clear start and end, create a data exclusion under Tools › Adjustments › Exclusions, as soon as you spot the problem. Then adjust CPA or ROAS targets, as Google advises.

Every layer leaks. Diagnose top down; most teams stare at the Google Ads report, the one place the problem never is.

Mistakes that make broken tracking worse

• Creating a brand-new conversion action "to start fresh". Smart Bidding loses the old action's history. Fix the existing one.
• Switching bid strategies mid-outage. Moving to Manual CPC because "the AI is broken" resets learning on top of the data problem.
• Making GA4 imports Primary as a patch. It double counts the moment the native tag returns.
• Hard-coding consent to granted. Conversions return, and so does your legal exposure in Europe and the UK.
• Judging recovery after two days. Imports lag up to 24 hours and modelling needs time to train. Give it a week.

How to stop it breaking again: a monitoring routine

Honestly, most tracking failures are found by the finance team, weeks late. A small routine catches them in a day.

The daily alert is the cheapest insurance you'll buy. A rule or script that emails you when conversions fall below half the trailing average takes ten minutes. For lead-gen, the weekly reconciliation matters more: 120 leads in Google Ads against 70 in the CRM means a counting problem, a spam problem, or both. Our landing page examples show form patterns that track cleanly.

Worked scenario: a Toronto SaaS company selling into the UK

Illustrative example. The company and numbers are invented to show the method.

A Toronto B2B software company spends CAD 12,000 a month on Google Ads. Most of it targets Canada and the US, but since opening a London sales office it puts about a third into UK and EU campaigns. In July, Google Ads reports 180 demo bookings. In August, after the website team swaps to a new cookie banner for the European launch, it reports 95. The CRM, which the sales team trusts more, shows 168 and 160 paid-search demos for the two months.

Two problems turn up in the first hour. The new banner correctly defaults UK and EU visitors to denied, but its update command only fires on the desktop layout, so mobile visitors who accept are still treated as denied. UK and EU conversions fell by about 85%, while North American campaigns barely moved, which is what pointed at consent in the first place. Separately, the GA4 generate_lead key event has been imported as Primary since a 2024 migration, alongside the native demo-booking tag. Roughly 40 of July's 180 conversions were duplicates.

In three days the CMP vendor patches mobile, the GA4 import moves to Secondary, the tag switches to "One" per click, and enhanced conversions starts sending hashed work emails. A data exclusion covers the broken days. Two weeks later Google Ads reports 148 conversions against 158 CRM demos, a gap consent rates explain. Target CPA is reset about 20% higher, because the old target was set against inflated data.

The account never had 180 conversions; the "drop" was partly a correction. That's typical.

Running Meta Ads too? Our Pixel and Conversions API guide covers the same problems there, and Google Ads vs Meta Ads helps split budget once both are measured. Before switching on AI Max for Search, make sure the conversions it chases are real.