Short answer: In Google Analytics 4, conversions are called key events. For a service business the most important things to track are form submissions, clicks on the phone number, clicks on WhatsApp and clicks on the email address; for an online shop, purchases with their value. The most reliable set-up is through Google Tag Manager, checked in DebugView before the data is used for any decisions.
Without conversion tracking you cannot know whether your business comes from Google, Instagram, word of mouth or existing clients. Worse still, without conversion data Google Ads and Meta optimise campaigns for clicks rather than enquiries. That is why conversion tracking is the first job we do with every new client, before any ads and before SEO.
Key terms in GA4
- Event: any action on the site, such as a page view, a scroll, a click or a form submission.
- Key event: an event you have marked as important to the business. In 2024 Google renamed conversions in GA4 to key events, and the word conversions stayed in Google Ads.
- Parameters: extra data sent with an event, such as which form was submitted or the purchase value.
What to track, by type of business
| Business type | Primary conversions | Secondary conversions |
|---|---|---|
| Service business | Form submitted, phone click | WhatsApp click, email click, map click |
| Online shop | Purchase with value | Add to basket, checkout started |
| B2B and manufacturers | Quote request | Catalogue download, email click |
| Hotels and accommodation | Booking or enquiry | Booking button click, phone click |
Primary conversions are the ones you optimise your ads for. You track secondary conversions too, but you do not mix them with the primary ones, because a map click is not the same as a submitted enquiry.
Set-up step by step
1. Install Google Tag Manager
Tag Manager is a container that holds all your tracking code: GA4, Google Ads, the Meta pixel. On WordPress it is added with one snippet in the header or through a plugin. The advantage is that you do not have to touch the site for every later change to tracking.
2. Form submissions
The most reliable method is a dedicated thank-you page after submission, such as /thank-you/, and an event that fires when that page is viewed. If the form does not lead to a new page, use the event the form fires after a successful submission. With Contact Form 7 that is the wpcf7mailsent event. Do not track clicks on the Send button, because they count even when the form fails validation.
3. Phone, WhatsApp and email clicks
In Tag Manager, create a trigger for clicks on links whose URL starts with tel: or mailto:, or contains wa.me. Have each one send a separate event, such as click_phone and click_whatsapp, so you can tell them apart in reports. Bear in mind that a click is not a conversation: some people click and then change their mind. If phone calls are your main source of business, consider call tracking with a dedicated number.
4. Purchases in an online shop
For WooCommerce there are plugins that send the standard e-commerce events: view_item, add_to_cart, begin_checkout and purchase, with value and order ID. The order ID matters because it prevents double counting when a customer refreshes the confirmation page.
5. Mark your key events
In GA4, go to Admin, then Events, and mark which ones are key events. Then import them into Google Ads or, better still, use the Google Ads conversion tag directly, and decide which are primary.
6. Test before you trust
Switch on preview mode in Tag Manager, submit a test form, click the phone number and check in GA4 DebugView that the events arrived with the right names. Only then publish the container. Half the mistakes we find in accounts are tracking set-ups that were never tested.
Cookie consent
If you have visitors from the EU or the UK, or advertise there, Google requires Consent Mode v2 and a consent banner, and GDPR requires that visitors are informed about how their data is processed. A properly configured banner with Consent Mode lets Google model some conversions even when a user declines cookies.
The most common mistakes
- Tracking button clicks instead of successful form submissions.
- Duplicate code: GA4 installed both through the theme and through Tag Manager, so everything is counted twice.
- Purchases without an order ID, so every refresh is counted again.
- Too many primary conversions in Google Ads, so the algorithm chases easy clicks instead of enquiries.
- Internal traffic: staff testing the site skew the data. Exclude your office IP address.
Frequently asked questions
Do I need the Google Ads tag as well if I have GA4?
Importing from GA4 can work, but the Google Ads tag is usually more accurate and faster for campaign optimisation. We usually use both, with a clear decision about which is primary.
How long does it take to collect data?
The first data arrives straight away, but you need at least a month before drawing serious conclusions, and longer on smaller sites.
Can I track calls that did not come through the site?
Partly. Clicks on the number in your Google profile show up in the profile’s performance stats, and Google Ads tracks calls from ads itself. For the full picture, it is best to ask every new client how they heard about you.
Conclusion
Good measurement is the foundation for everything else: without it SEO is a matter of faith and ads are a gamble. If you are not sure whether GA4 is tracking what it should, we will check it as part of a free audit, and we set up tracking as the first step of every digital marketing engagement.
Related: Meta pixel and Conversions API · Measuring digital marketing ROI
