GA4 tells you nothing useful? Set up key events, step by step

If GA4 shows visitors, pages and countries but a column of zeros under key events, nothing has been marked as a key event, and until something is, it can't tell you whether the website brought in any enquiries. The fix takes four steps: decide what counts, make sure an event exists for it, mark it with the star, and test it.

GA4 counts page views and a few interactions by itself, but it doesn't know which of them matter to you. For a website, Google marks only one event as a key event by default: purchase, which a business that takes enquiries rather than payments may never send.

First, the names, because much of the advice online uses old ones

GA4's vocabulary has changed twice, and plenty of guides, videos and plug-ins still use the old words.

• Goals. Universal Analytics, the previous version, called your important actions goals. Google says standard Universal Analytics properties stopped processing data from 1 July 2023, so any guide that mentions goals is about software that no longer collects anything.
• Conversions. GA4 at first called them conversions, which is why older GA4 guides tell you to "mark as conversion".
• Key events. Google's release notes for 27 March 2024, in a copy archived in May 2024, announced the change that still applies: "From now on, events that measure actions that are important to the success of your business are now called 'key events.'"

The word conversion didn't disappear, but it now means something narrower. Google's page on conversions and key events puts it like this: "A 'conversion' now refers to an important action that you want to use to measure the performance of your ad campaigns and optimize your bidding strategy". Put simply, key events are for understanding your business, and conversions are for running Google Ads.

Even the buttons have moved. Google's current help describes a star beside an existing event, where older guides describe a switch. If what you see doesn't match a guide, check the date on the guide before you check your settings.

Step 1: decide what counts

Pick two or three actions that genuinely mean business, not ten that merely mean activity. For most small firms, that's:

• an enquiry form sent;
• a booking made, if you take bookings online;
• a purchase, if you sell online.

Taps on your phone number or email address are worth recording too, but as separate events, because a tap isn't the same as a call. Whatever you record, send a real enquiry through your own form afterwards and check it's counted, which is also the first thing to look at when Google Ads aren't bringing in enquiries. Google allows up to 30 key events on a standard property, and you won't need anything like that many.

Step 2: make sure there's an event to mark

A key event is an ordinary event with a label on it, so something has to send the event first. There are three ways to do that, from least to most work.

If your form sends people to a thank-you page

This is the easiest reliable route, and it needs no change to your website. GA4 already records a page_view every time someone lands on the thank-you page, so you create a new event from that. Google's guide to creating events walks through exactly this case:

1. In Admin, under Data display, click Events.
2. Click Create event.
3. Give it a name with no spaces or special characters, such as enquiry_sent.
4. Choose Create without code, pick page_view as the event, and enter the address of your thank-you page.
5. Click Create. You can mark it as a key event on the same screen.

The page address must be one that only appears after a successful enquiry. If people can reach the thank-you page by browsing, the count will be wrong.

If there's no thank-you page: the automatic form events

GA4's enhanced measurement can record form interactions without any code, as form_start and form_submit. Google describes form_submit as firing "when the user submits a form".

Notice what that doesn't say: that the form was sent successfully. It also fires for every form on the site, a newsletter box as much as your enquiry form, told apart only by form_id and form_name. Before you rely on it, test it with a real enquiry and look at which forms it fires on.

The most reliable route: an event your website sends

Ask whoever built your site to send an event at the moment the form confirms it has been sent, either in the site's code or through Google Tag Manager. Google's list of recommended events includes one made for this, generate_lead, which Google says is for when a user "submits a form or a request for information". Using Google's own name keeps your set-up in line with its documentation.

Step 3: mark it as a key event

You need the Marketer role or above in the property. Then, following Google's key events set-up page:

1. In Admin, under Data display, click Events.
2. Find your event in the list.
3. "Mark the event as a key event by clicking the star icon next to it."

A new event may not appear in the list until GA4 has received it once, but you can still mark it in advance by creating it with the same name.

Step 4: test it

Send a real enquiry through your own form, then open the Realtime report. Google's help on key events says Realtime updates "a few minutes after a user triggers a key event", while standard reports can take "up to 24 hours".

If nothing arrives, there are three usual suspects: the thank-you page address doesn't match exactly, the form doesn't reload the page so form_submit never fires, or you declined the consent banner and GA4 didn't record your own visit.

Then check it against reality for a month. If GA4 counts twelve enquiries and your inbox has twenty, something isn't being recorded.

Reading the results

Marking an event doesn't work backwards. Google's key events help is explicit: "It doesn't change historic data." Last year's enquiries will stay invisible, and the count starts from the day you set it up.

Once it's running, many standard reports gain a useful column. Google names the Landing pages and User acquisition reports among those with a Key events column, and you can pick one key event from its menu to see which channels and pages bring in enquiries. That column is what makes the five GA4 reports you need worth reading once a month.

If you run Google Ads, the key event is also what you build an Ads conversion from, so both tools count the same thing, and Google explains how in creating Google Ads conversions from key events. Whether the ads are worth running at all comes down to a separate sum, the break-even sum for Google Ads.

Consent changes the numbers

GA4 only records visitors whose data it's allowed to collect. If your site asks for consent before analytics runs, which is still the safe reading of the UK rules for GA4, people who decline aren't counted, and your key events will undercount real enquiries. That's expected, and it isn't a reason to switch analytics on without asking.

The UK rules on cookie banners for analytics aren't settled for GA4, and nor is the advanced version of Google Consent Mode. That's also why your own inbox, not GA4, is the final word on how many enquiries you had.

What Google doesn't make clear

• The interface keeps changing. Menu names, buttons and even Google's own help pages have changed since 2024, and two of Google's pages today describe the same step differently, one with a star and the other with a switch. The steps above match Google's help as it stood on 28 September 2026.
• The automatic form events. Google doesn't say whether form_submit waits for a successful send, or how it treats forms that don't reload the page. I'd treat it as a starting point to test, not a measure to trust.
• Phone taps. Google's list of automatic enhanced measurement events doesn't include taps on a phone number, and it doesn't say whether a tel: link counts as an outbound click. Test it in Realtime, or have a dedicated event set up.

If you'd rather have it set up and checked for you, our GA4 and tracking fix does exactly that for a fixed £2,500, in about two weeks.