Tracking is almost always the afterthought. The campaign brief is written, the creative is approved, the media plan is locked — and then someone asks, "are we set up to measure this?" Usually two days before launch.
By that point there's no time to fix anything properly. So the campaign launches on a broken foundation, the data comes back unreliable, and nobody can tell whether the campaign actually worked or not. The budget is spent either way.
This checklist exists to prevent that. It covers the GA4 checks that need to happen before any campaign goes live — the foundation layer that everything else depends on. Getting this right is step one of three in a proper campaign measurement strategy. But it's the step most teams skip entirely.
Why GA4 Health Is Step Zero
A campaign measurement strategy has three layers. The first is a clean, accurately configured GA4 instance. The second is a campaign-specific measurement plan built before launch. The third is the data infrastructure to support analysis beyond what GA4's UI can show you.
You cannot build on a broken foundation. If your GA4 property has misconfigured events, missing conversion tracking, or attribution errors baked in, everything you measure during the campaign will be wrong. You'll be optimising based on bad data — and you won't know it.
Running a pre-campaign GA4 audit isn't just a technical exercise. It's a prerequisite for making any of the campaign data that follows trustworthy.
The Pre-Campaign GA4 Checklist
1. Conversion events are confirmed and firing correctly
This is the most important check. Before a campaign launches, verify that every conversion event you plan to optimise against is actually firing — and firing accurately. Not just that it exists in GA4, but that it's recording the right interactions, on the right pages, with the right parameters.
Conversion events to verify before any campaign:
- Purchase or lead form submission (your primary KPI event)
- Add to cart, begin checkout (e-commerce funnel events)
- Any micro-conversions the campaign is designed to drive
- Confirmation that purchase events include transaction_id, value, and currency
2. UTM parameters are consistent and standardised
Every campaign URL needs UTM parameters. But UTM inconsistency is one of the most common GA4 problems we see — the same channel appearing as five different source/medium combinations because different people on the team are tagging links differently.
Before launch, establish and enforce:
- Consistent utm_source naming (google not Google, not google-ads)
- Consistent utm_medium values (cpc, email, social — not paid, ads, sponsored)
- utm_campaign names that will make sense in reporting three months from now
- utm_content for any A/B creative variants you're testing
If your UTMs aren't consistent going in, your channel attribution data will be fragmented coming out.
3. Internal traffic is excluded
If your team, your agency, or your developers are browsing the site during a campaign, their sessions will pollute your data. Internal traffic filters need to be active before launch — not added after you notice the numbers look inflated.
- Office IP addresses excluded via GA4 internal traffic filter
- Developer and staging environments excluded
- Agency IPs excluded if they're doing QA or testing
4. Payment processors are excluded from referral sources
If you're running any campaign that drives e-commerce conversions, this one matters. When a user clicks through to your payment processor (Stripe, PayPal, Klarna) and returns to your confirmation page, GA4 can attribute that session to the payment processor as the source — not the original campaign.
The result: your campaign looks like it drove fewer conversions than it actually did, and your payment processor appears as a traffic source. Exclude payment processors from referral sources before any e-commerce campaign launches.
5. Attribution model is appropriate for your campaign type
GA4 defaults to data-driven attribution, but not every campaign benefits from the same model. Before launch, confirm that your attribution settings make sense for the campaign you're running — particularly the attribution window.
- Short attribution window (7 days) for impulse-purchase campaigns
- Longer window (30–90 days) for considered-purchase or B2B campaigns
- Cross-channel view if the campaign is running across multiple platforms simultaneously
6. Data retention is set to 14 months
GA4 defaults to 2-month data retention. If you're running a campaign now and want to compare performance against the same campaign next year, you need 14 months of retention active. Change this before the campaign starts — you cannot recover data that's already been deleted.
7. No duplicate event firing
Duplicate events inflate every metric. A purchase event firing twice per transaction doubles your reported revenue. A form submission event firing twice per submission doubles your reported conversions. Check for duplicates before launch — especially if the site has recently been updated or new tags have been added.
8. Device and regional coverage is verified
This one is often overlooked. If your campaign is targeting mobile users, verify that your tracking and conversion events are working correctly on mobile — not just desktop. The same applies for regional campaigns: if you're targeting a specific geography, confirm that sessions from that region are being tracked accurately.
Run This Checklist Automatically
Working through this manually before every campaign takes time most teams don't have. GA4 Health Check runs all 50+ checks automatically — including conversion event verification, UTM consistency, internal traffic filters, payment processor exclusions, and duplicate event detection — and returns a scored report in 60 seconds.
Run it before every significant campaign launch. The cost of finding a problem before launch is a few minutes. The cost of finding it after is your entire campaign budget.
Run your pre-campaign audit — $79 →
What Comes After This Checklist
A clean GA4 instance is the foundation — but it's only one third of a proper campaign measurement strategy. Once your tracking is verified, the next step is building a measurement plan specific to the campaign: defining success, mapping the mini funnel, identifying every touchpoint that needs to be tagged, and establishing the KPIs that will tell you whether the campaign actually worked.
That's covered in part two: Building a Campaign Measurement Strategy.
