Google Analytics Audit: Our Detailed GA4 Audit Strategy

A Google Analytics audit is now a crucial step for any business that depends on GA4 data to make vital decisions. Since the transition from Universal Analytics, many setups were hastily configured and never thoroughly validated. This often results in reporting that seems accurate at first glance but hides significant inaccuracies.

As a Google Analytics audit agency, Versich has conducted GA4 audits for over 200 businesses across various industries and sizes. This includes large organizations like Revolut and small to medium eCommerce firms. We also possess extensive experience working with GA360 properties, which have stringent data accuracy and governance requirements.

For instance, in a recent assignment, we performed a GA4 audit for five Shopify websites, achieving a 25% boost in customer visibility across channels and a 20% rise in customer events through Facebook and Google Ads.

In this blog, we'll guide you through our typical approach to a GA4 audit, highlighting what we check, common issues we encounter, and how to convert audit results into a clear action plan.

What Is a Google Analytics Audit in the GA4 Era (and Why Do You Need One)?

Since the transition to GA4 in 2023, the definition of a “Google Analytics audit” has evolved significantly. It’s now more than just looking at some settings or validating reports. It involves examining how GA4 is configured, how data is gathered, and whether the reported data supports your decision-making processes.

When our Google Analytics specialists conduct GA4 audits for clients, we consider them a comprehensive data quality evaluation. The aim is to ensure that the data accurately reflects real user behavior and can be relied upon for making marketing and product decisions.

A GA4 audit is a systematic review of the entire setup. This encompasses property settings, data streams, event and conversion tracking, filters, integrations, and tagging through tools like Google Tag Manager (GTM). We also analyze how data flows between systems to confirm that critical business actions are being captured correctly.

The focus is less on simply “turning features on” in the interface and more on ensuring data accuracy and usability. Often, we find that while tracking appears to work technically, the data can be incomplete, duplicated, or misaligned with business objectives, rendering it useless for analysis.

From our expertise in marketing analytics consulting, we recommend conducting GA4 audits at least once a year. They are especially important after major changes like website redesigns, new funnel implementations, market expansions, or GA4 updates related to attribution and consent mode. These updates can easily disrupt tracking without anyone realizing it. We also advise performing a GA4 audit before building marketing dashboards to ensure the data's reliability.

Moreover, this process significantly differs from audits of legacy Universal Analytics setups. GA4 lacks views, utilizes an event-based data model, and employs varied attribution logic. Changes in data retention and sampling behavior indicate that old audit checklists are no longer applicable and require a complete rethinking.

Why Your Business Needs a Google Analytics Audit in 2026

Many of the GA4 setups we review were rushed during the 2022-2023 migration from Universal Analytics. These configurations are now driving reporting in 2026, often without anyone revisiting whether the data remains accurate or complete.

This can become problematic since GA4 isn’t inherently 100% accurate. It depends on JavaScript tracking, which inherently leads to some data loss. Factors like ad blockers, browser privacy settings, cookie consent banners, server latency, and tracking script errors can prevent events from firing. Consequently, a 10-15% discrepancy between GA4 and platforms like Shopify or CRM systems is typical in many setups.

The critical issue lies not in minor discrepancies but in erroneous data patterns. When tracking is misconfigured, businesses tend to overinvest in channels that seem effective due to duplicated conversions, incorrect attribution, or flawed tagging logic. We have observed instances where paid campaigns appeared profitable in GA4 but were genuinely underperforming once tracking was sorted.

Several clear indicators signify the need for a GA4 audit. A sudden traffic drop following a website redesign often suggests broken tracking or missing tags. Conversion counts that don’t align with your CRM or payment processor indicate problems with event setup or deduplication. Unexplained spikes in “Direct” traffic usually point to missing UTM parameters or attribution issues. Missing data concerning specific products, pages, or regions commonly signals tracking gaps.

Legal and privacy changes have also contributed to GA4 setups being more vulnerable. Regulations like GDPR, CCPA, and the ePrivacy directive directly impact when and how tracking can operate. If consent mode or tagging is improperly configured, a significant portion of data might be lost without your knowledge, or you could collect data in ways that pose compliance risks.

Common Reasons for Data Inaccuracies in GA4

In most GA4 audits we conduct, issues rarely stem from a singular major mistake. Instead, they arise from a combination of minor configuration problems that accumulate over time and distort the data.

1. Tracking through integrations

We frequently encounter challenges with native GA4 integrations, particularly with platforms like Shopify. These integrations are designed for standard setups, typically depending on Shopify’s native checkout and predetermined tracking logic. Problems arise when setups become overly complicated. For instance, custom checkout options, additional scripts, or third-party applications can lead to tracking failures, resulting in missing transactions, duplicated events, or jumbled channel data.

In one audit, we discovered that a website relied on Google and YouTube apps to generate the e-commerce data layer. While this setup technically satisfied GA4’s Enhanced Ecommerce schema, it had one major drawback: the data layer couldn’t be customized to meet the client’s needs.

This limitation didn’t necessarily disrupt tracking but significantly hampered the data’s usefulness for analysis and decision-making. Reports may look appealing at first glance but lack the depth necessary to drive impactful changes.

Due to these constraints, we often recommend transitioning to a GTM-only implementation. This approach grants the client complete control over the data layer, allowing them to rectify inaccuracies, standardize tracking, and capture the additional data essential for advanced analysis.

2. Buggy plugins

Another common complication arises from plugins malfunctioning. Certain plugins, especially those influencing performance, security, or cookie consent, can obstruct or delay tracking scripts.

This can prevent GA4 tags from firing correctly, resulting in gaps in session data, missing events, or incomplete user journeys. These issues typically linger in the background and come to light only during an audit.

3. Teething problems with trigger selection

Trigger configuration is among the most prevalent technical mistakes we observe. A typical example is using a pageview trigger for conversions.

If the conversion is linked to a “thank you” page, users may simply reload that page and trigger the same conversion multiple times. This artificially inflates performance metrics and makes certain channels appear more effective than they truly are.

4. Website redesigns

Tracking often fails after website updates. We regularly audit setups where tracking was designed for the previous layout and wasn’t updated following a redesign.

Modifications to URLs, buttons, forms, or page structure can impede events from firing or redirect them to inappropriate elements. This results in vital interactions being either lost or inaccurately recorded without anyone noticing.

Prepping for a Google Analytics Audit

Before starting any GA4 audit, we ensure we have appropriate access levels and a solid understanding of how the business utilizes its data. Without this, it’s easy to overlook critical issues or misinterpret what the tracking aims to measure.

In practice, preparing for an audit is straightforward yet critically important. Here’s what we request before we begin:

• Access to GA4 (Admin and Editor roles) so we can review all property settings, events, conversions, and configurations without barriers.

• Access to Google Tag Manager (GTM) to double-check how all tags, triggers, and variables are set up and functioning.

• Access to Google Ads (if applicable) to verify conversion imports, attribution alignment, and tagging consistency.

• Access to the consent management platform (e.g., Cookiebot, OneTrust) to understand how consent influences tracking and whether data is being blocked.

We also utilize a specific set of tools during every audit to validate data and troubleshoot issues:

• Tag Assistant (Chrome extension) to verify whether tags are firing correctly on the website.

• GA4 DebugView for real-time inspection of event-level data, confirming sound tracking logic.

• Real-time reports in GA4 to swiftly validate whether key actions are being captured.

• Server logs or CRM exports for cross-referencing GA4 data against actual transactions, leads, or backend records.

This setup allows us to operate efficiently and concentrate on identifying genuine data problems rather than merely guessing how the tracking is implemented.

What Our Google Analytics Audit Usually Covers

If a client has a specific concern, we prioritize that first. Otherwise, we conduct a structured audit that encompasses critical areas affecting data accuracy and usability, including GTM implementation, GA4 settings, data streams and tagging, event and conversion tracking, traffic quality and filters, cross-domain tracking, integrations (Google Ads, Search Console, BigQuery, CRM), and privacy and consent configurations.

GTM Implementation

We always initiate the audit with Google Tag Manager because most tracking challenges originate there. It’s where all the tags, triggers, and event logic are defined, meaning even a minor misconfiguration can impact all subsequent data.

For example, in one audit, our eCommerce Google Analytics consultants found that the GTM script was installed twice in the website’s source code. As a result, every tag was firing twice, causing duplicated events and artificially inflated conversion figures. The solution was straightforward: use a single installation method - yet the impact on data accuracy was far more significant than anticipated.

GA4 Settings

This portion of the audit focuses on confirming some critical property-level settings that are often misconfigured and subtly affect data quality.

We first examine data retention settings. GA4 free properties only retain event-level data for either 2 or 14 months. Our general recommendation is to set this to 14 months unless there’s a compelling reason not to. The reality is, if you only have 2 months of data, your ability to effectively analyze trends and compare performance over time is severely limited.

Another vital step is ensuring Google Signals is properly set up. We verify it’s enabled and that you’ve acknowledged user data collection. This configuration allows GA4 to gather demographic data like age, gender, and interests, which is advantageous for remarketing but requires adherence to GDPR and CCPA consent parameters.

We also assess the Reporting Identity setting. Typically set to “Blended,” this is generally recommended for websites with login features. It combines device ID, user ID, and modeled data to enhance user identification across devices. It’s crucial to note that this doesn’t alter the underlying data; it merely adjusts how it’s reported. Testing various options to discover which works best for your needs is worthwhile.

Finally, we scrutinize your internal traffic definitions and unwanted referrals under Data Settings > Data Filters. This entails excluding office IP addresses, test environments, and any known referral sources that should not appear in your reports. This way, the data more accurately mirrors real user behavior rather than internal activity.

Checking Data Streams and Tagging

In this section, we confirm that GA4's data structure is clean and that tracking functions consistently across the site.

First, we verify that there is only one primary Web data stream for the main domain (like www.example.com), along with any needed app streams. We often find duplicate, test, or outdated streams still active, which we either label plainly or remove to prevent confusion in your reports.

Next, we check that the measurement ID (G-XXXXXXX) in the Web stream aligns with what’s deployed via GTM or gtag.js on all production pages. A mismatch can lead to fragmented data or sessions being divided across properties.

Finally, we review key pages using browser developer tools or tag debugging tools to ensure the GA4 tag fires only once per page. This helps us identify double-tagging issues, which can occur with both GTM and hardcoded gtag.js active simultaneously and inflate metrics.

Auditing Event and Conversion Tracking

In this phase, we verify if your primary user actions are tracked correctly and whether the data accurately reflects your business operations.

We begin by checking that each tag fires as intended, with the correct trigger in place. Even if tags are present, incorrect triggers can result in events firing too early, too frequently, or not at all.

Subsequently, we examine the Events list in GA4 Admin. We look for noisy or redundant events, inconsistent naming (such as “form_submit” vs. “formSubmission”), and any deprecated events still firing. Tidying this up is crucial for making reporting usable and avoiding confusion.

Next, we align your essential business actions with clearly defined GA4 events. This typically includes actions like contact form submissions, addtocart, begin_checkout, purchases, newsletter sign-ups, or trial starts. Every significant step in the user journey should have a dedicated event with consistent naming and logic.

We also assess which events are tagged as conversions. Only genuinely successful actions should be included - think purchases, qualified leads, or booked demos. Low-intent actions like scrolling or page views shouldn’t be marked as conversions as they distort performance reporting.

Auditing Attribution

Attribution is one of the areas where we commonly find misleading data, particularly when campaign tagging is inconsistent or neglected altogether.

We begin by assessing how conversions are distributed across channels, looking for any patterns that don’t resonate with your actual marketing operations. For example, conversions might be misattributed to Facebook as “Organic Social” even when there are active paid campaigns. While this isn’t always incorrect, it often indicates the need for a review and standardization of your campaign tagging, especially with Meta ads.

A frequent issue involves traffic being classified as the “Unassigned” default channel group. During one audit, we observed that 6.95% of users were labeled this way, usually because UTMs didn’t follow Google’s channel grouping conventions.

For instance, if you label “MetaAds” as a source and “Allproductadvantage” as a medium, GA4 won’t categorize the traffic correctly. In such cases, we advise adopting a consistent format like “Facebook” for source, “cpc” for medium, and “Allproductadvantage” for campaign. This will enable GA4 to classify the traffic under Paid Social accurately.

Fixing attribution is vital for paid search analysis, necessitating accurate classification. Once UTM tracking adopts a consistent structure, channel reporting becomes clearer and more reliable, facilitating sound decision-making.

Form, Lead and Micro-Conversion Tracking

This segment of the audit focuses on B2B websites or businesses providing services, where lead generation is paramount.

We ensure that all lead forms - including contact, quote, demo bookings, and newsletter sign-ups - track effectively using the appropriate form_submit events or equivalent logic. Each form should clearly indicate what occurs upon successful submission.

For instance, during one audit, we discovered that a “GA4 Email Signup Form Submit” tag was disabled and wrongly configured from the outset. The trigger activated as soon as a user began typing their email address, rather than when they actually completed the signup.

Consequently, the data counted individuals merely accessing the sign-up form rather than those who completed the process. This discrepancy meant that the conversion figures did not accurately represent the situation.

Our recommendation was to adjust the trigger to ensure it activates only upon successful submissions. We also suggested renaming the event to align with GA4 naming conventions (for instance, “form_submit”) and checking if it could utilize Enhanced Measurement instead of being set up manually.

We advise against tracking conversions by monitoring thank you page views because this method is unreliable. Users may reload the page multiple times, leading to double-counting and various other issues with the numbers.

eCommerce and Revenue Tracking

In the realm of eCommerce performance analytics, we assess the entire purchase funnel to ensure all key GA4 eCommerce events are correctly set up. These events include viewitemlist, viewitem, addtocart, begincheckout, addpaymentinfo, and purchase.

We also verify that GA4 revenue aligns with the source of truth, such as Shopify or WooCommerce. For example, we may compare revenue figures and transaction counts between GA4 and Shopify for a specific timeframe - like 2026-03-01 to 2026-03-07 - to identify discrepancies and ascertain where data is missing.

Along with ensuring all events are triggering, we check that essential variables are accurately recorded in the data layer. In one audit, we found that the addtocart event triggered correctly, but crucial information like price and item name wasn’t being captured. We also observed that the underlying technology still followed the old UA methodology, with terms like “id” and “name,” which don’t align with GA4's requirements.

Furthermore, we ensure that user data is included in the purchase event. Sometimes, fields like email or phone number are omitted from the data layer. However, if this data is included, it enables businesses to enhance conversions across platforms like Google Ads and Meta, improving attribution accuracy.

Typical issues we observe include missing refund tracking, handling multiple currencies without proper conversion, and insufficient data on mobile devices compared to desktops. While these problems may not entirely disrupt reporting, they render the figures less reliable and harder to act upon.

Traffic Quality, Filters and Bot Exclusion

Maintaining clean traffic is as crucial as ensuring accurate event tracking. Infiltration of low-quality or internal traffic skews metrics like conversion rate, bounce rate, and channel performance.

We begin by scrutinizing GA4 traffic by channel, medium, and source to identify anomalies. Unexplained spikes in “direct” or “referral” traffic - particularly after campaign launches - typically suggest issues with attribution, missing UTMs, or tracking malfunctions.

Although GA4 aims to block known bots automatically, we still examine traffic for suspicious hostnames and referrers, such as spam domains. If necessary, we recommend adding further exclusions to maintain clean data.

We also verify UTM and campaign tagging conventions, which are especially critical for paid media analytics. If parameters like utmmedium aren’t consistently applied - for example, using “paidsocial,” “cpc,” and “social” interchangeably - the reporting can fragment, complicating channel performance analysis.

Cross-Domain and Subdomain Tracking

In this aspect of the audit, we ensure that user journeys remain intact as they navigate between domains or subdomains.

We review the GA4 cross-domain settings to verify that all relevant domains are included - such as the main site, blog, and any third-party checkouts or authentication domains. This prevents sessions from being disrupted when users traverse different domains.

Missing cross-domain tracking typically manifests as fragmented sessions, inflated user counts, or atypically high direct traffic on secondary domains. This complicates efforts to obtain a comprehensive understanding of the complete customer journey.

If a business operates on multiple domains for various brands or languages, we evaluate whether to track them within a single GA4 property with cross-domain tracking or split them into separate properties. For instance, in a SaaS model with a marketing site at example.com and a product at app.example.com, proper cross-domain tracking is essential to treat users who sign up as a single session rather than new users when transitioning between domains.

Integrations - Google Ads, Search Console, BigQuery and CRM

One of the critical areas where GA4 shines for marketing optimization is through integrations. It’s in this segment that we most frequently identify missing or broken links, which can significantly limit the value of the data received.

We initiate by examining the GA4 Admin > Product Links section, confirming that Google Ads, Search Console, and BigQuery (if applicable) are correctly configured and operational. We ensure that Search Console is properly linked so that GA4 can access organic search query and landing page data, along with verifying that Google Ads receives accurate conversions.

For Google Ads, we check that auto-tagging is enabled and that GA4 conversions are being properly imported into Google Ads. If these settings are off, you could be basing bids on incomplete or erroneous data, negatively impacting campaign performance.

We also confirm that the Search Console integration is functional, ensuring GA4 is obtaining the necessary organic search query and landing page data. If BigQuery is in use, we check that daily exports are operating smoothly, that the schema aligns with expectations, and that the data location-be it EU or US-meets your data residency requirements.

Privacy, Consent, and Compliance

Since 2024, privacy regulations have undergone significant changes, and your GA4 setup must align with these updates-this is a key part of our evaluation. It’s about more than just ensuring that everything technically operates correctly.

First, we verify that tracking respects user consent-this involves ensuring that GA4 tags only fire after users have accepted analytics cookies, as required by your consent banner.

We also check that Consent Mode (v2, if that’s the latest you’re using) is configured accurately, especially for EU traffic. We confirm that consent signals are being transmitted from the Consent Management Platform (CMP) to Google tags and that tracking behavior adjusts accordingly.

Subsequently, we review data controls like IP anonymization and location settings. These must comply with your organization’s privacy policy and not collect more personal data than necessary.

Finally, we distinguish between compliance issues and optimization opportunities. Anything presenting a legal or regulatory risk gets flagged for urgent attention, while other matters become avenues for enhancing data quality and performance.

Interpreting Findings - Building an Action Plan

An audit is only beneficial if its findings lead to an actionable plan. After completing the audit, we typically have a clear scope of work to address GA4 and enhance data accuracy, following which we move on to the implementation of fixes and the establishment of additional tracking.

Our findings are usually categorized into three priority tiers: critical issues affecting data trust, legal compliance, or revenue reporting that need immediate resolution; important issues that aid attribution and tracking but don’t hinder decision-making; and low-priority issues that focus on organization and tidiness.

Each finding is documented in a straightforward, clear format-often listing the issue, its impact, recommended fixes, responsible parties, and deadlines. This allows progress tracking and ensures that nothing is overlooked.

For instance, you might decide to resolve duplicate GA4 tags at checkout by mid-May 2026 and establish accurate server-side tracking for purchases by the end of Q2 2026. Such clarity turns audit insights into actionable improvements.

Regular audits are essential. We recommend conducting them at least every six months for high-traffic sites and annually for smaller ones, to keep tracking accurate as your site and configurations evolve over time.

Once your GA4 audit is complete and all data issues are resolved, you may wish to advance your data journey by beginning to build Looker Studio dashboards for more in-depth data exploration.