Conversion tracking is how Google Ads finds out which clicks turned into an enquiry, a booking or a sale. Every cost-per-lead figure in your account, and every bid Google’s automation places, rests on it. I set up and repair conversion tracking for UK businesses that run Google Ads, so that the numbers in the account match what actually arrives in your inbox, on your phone and in your till.
Why tracking has to be right before spend goes up
With Smart Bidding, Google sets the bid for each auction based on how likely that click is to convert. It optimises towards whatever you have told it counts as a conversion. If a visit to the contact page counts as a lead, Google gets very good at finding people who look at contact pages, and the campaign appears to perform while the phone stays quiet.
The reporting suffers in both directions. Count the same enquiry twice and a campaign looks cheaper than it is, so you keep funding it. Miss the phone calls and a campaign that fills your diary looks expensive, so you cut the wrong thing. I would rather fix the measurement before changing a single bid, because every later decision inherits it.
Who this suits, and who it does not
It suits you if the conversions Google Ads reports do not match the enquiries you can see, if you are about to switch to automated bidding or Performance Max, or if your sale happens offline after the first contact, as it does for solicitors, estate agents, private clinics and most B2B suppliers.
It suits you less if you spend a modest amount, receive a handful of enquiries a month and already ask every new customer how they found you. In that case a check of the existing setup is often enough, and a full rebuild would cost more than it tells you.
What I track, and what I keep out of bidding
The work starts by agreeing what a conversion means for your business. Usually that is a short list:
- Completed enquiry forms, counted when the submission succeeds rather than when someone presses the button.
- Calls from ads and calls from the website that last long enough to be a real conversation.
- Bookings made through an online booking system, including ones hosted on another company’s domain.
- Online purchases with their value and order number, so revenue is reported and nothing is counted twice.
- Qualified leads and closed sales from your CRM, sent back to Google once you know the outcome.
Softer signals such as clicks on an email address, brochure downloads or time on a page can be recorded, but I set them as secondary. Only primary conversion actions feed the bidding and the main Conversions column; secondary ones are visible for analysis and do not steer spend.
How the setup is built
Google Ads tag or GA4 import
Google Ads can count a conversion from its own tag or import a key event from GA4. For bidding I normally make the Google Ads tag the primary source, because it credits the conversion to the date of the ad click and picks up cross-device conversions that GA4 imports handle differently. GA4 stays in place for the wider picture of how people use the site. What matters most is that the same action is never primary from both sources at once.
Google Tag Manager
I build the tags in Google Tag Manager rather than pasting code into page templates. Each tag, trigger and variable is named so someone else can follow it, and form tracking listens for a genuine success message or a value pushed to the data layer, not a button click that fires even when validation fails.
Cookie consent, PECR and Consent Mode v2
Under the Privacy and Electronic Communications Regulations (PECR), a UK website must ask before it stores or reads anything on a visitor’s device that is not strictly necessary for the site to work. Advertising cookies, including the ones Google Ads conversion tags use, need consent. The ICO expects refusing to be as easy as accepting, so a banner with a large “Accept” and a hidden “Reject” does not meet the standard.
Consent Mode is how your cookie banner tells Google’s tags what the visitor chose. Version 2 passes four signals: ad_storage, analytics_storage, ad_user_data and ad_personalization. Google requires them for UK traffic if you want to keep using remarketing lists and some of its measurement features. In basic mode, Google’s tags do not load at all until the visitor agrees. Advanced mode loads the tags before a choice is made and sends cookieless pings when consent is refused, which Google uses to model missing conversions. Whether that is acceptable is a judgement for you and whoever advises you on data protection, and I explain the trade-off rather than make that call for you.
Enhanced conversions
Enhanced conversions take the email address or phone number someone typed into your form, hash it on the page and send the hash with the conversion. Google matches it against signed-in accounts to recover conversions that cookies miss, for example on Safari or when someone clicks on a phone and enquires later on a laptop. Because it involves customer data, it only runs when the visitor has agreed, your privacy notice needs to say it happens, and you need a lawful basis under UK GDPR. I check those three things before switching it on.
Phone call tracking
For businesses where most enquiries arrive by phone, as it is for many trades and clinics, calls matter more than forms. Call assets can show a Google forwarding number in the ad, and the same approach can swap the number on your website for visitors who arrived from an ad. I set a minimum call length that suits your business, so wrong numbers and quick hang-ups are not counted as leads. If you also need call recordings or calls from other channels, a separate call tracking service does that job better.
Offline conversion import
When the sale happens weeks after the enquiry, the useful signal is not the form but what happened next. Each ad click carries an identifier, the GCLID, which I capture in a hidden form field and store against the lead in your CRM. When the lead is qualified or becomes a customer, that outcome is uploaded back to Google Ads, by scheduled file or through your CRM’s own integration. Google accepts uploads only within a set window after the click, so the process has to run regularly rather than once a quarter.
Testing before anything is trusted
Every conversion action is tested with real submissions and calls, using Tag Manager’s preview mode and Google’s Tag Assistant, under both accepted and refused consent. I then compare the account’s figures with your own records for a couple of weeks. My guide to checking whether conversion tracking works covers the same checks if you want to run them yourself first.
Problems I see most often on UK sites
- Tags that fire before the banner is answered. The consent tool was added after the tags, and nobody moved them behind it.
- A consent default set too late. The default state loads after the Google tag, so the first page view ignores it.
- Thank-you pages counted every time. A lead action set to count every conversion records a refresh or a bookmark as a fresh enquiry.
- Double counting. A GA4 import and a Google Ads tag both set as primary for the same form.
- Lost click IDs. Booking widgets and payment pages on another domain drop the identifier, so the sale never links back to the ad.
- Calls missing entirely. A heating or electrical business tracks forms carefully while most of its work arrives by phone.
- Leftover actions. Conversion actions from the old Universal Analytics, which no longer collects data, still sitting in the account.
How I run the work
- Review. I look at the current conversion actions, tags, consent setup and recent figures, and compare them with what you know came in.
- Measurement plan. A short document listing each conversion, how it is recorded, whether it is primary and what value it carries.
- Build. Tags, consent, call tracking and any CRM capture, built on a test version of the container first.
- Test and publish. Real test conversions, then publication, then a watch on the live figures.
- Reconcile. After the first weeks, a comparison of reported conversions with your own records, and adjustments where they differ.
What you receive
- The measurement plan, with the settings for every conversion action.
- A documented Tag Manager container held in your business’s own account.
- A note of what the tracking collects and shares, so whoever maintains your privacy and cookie policies can keep them accurate.
- A test log showing what was checked and the result.
- A walkthrough call so you know where to look when the numbers change.
Cost and next step
I quote for tracking work in GBP, in writing, after I have seen the account and the site, because a single contact form and a shop with a CRM and call tracking are very different jobs. If you would rather have tracking looked after alongside the campaigns month by month, it is part of ongoing PPC management.
To start, send me your website and the Google Ads account ID, with a rough count of the enquiries you received last month. I will tell you how far the account’s figures are from that count and what I would fix first.